Class 10

UP Board Solutions for Class 10 Computer Science Chapter 3 Network: LAN and WAN

Network: LAN and WAN Long Answer Type Questions (8 Marks)

Question 1.
What is a Computer Network? What are its different types? (UP 2004, 05, 12, 13, 15, 19)
Or
What is LAN and what is WAN? (UP 2006, 10)
Or
What is meant by the following: (UP 2007, 09, 11)
(i) LAN
(ii) WAN.
Or
Explain WAN. (UP 2017, 18)
Or
Explain different types of Networks. (UP 2018)
Or
What is topology in a computer network? Write their types. (UP 2009)
Answer:
When computers and other devices such as printer are connected to each other through a medium then this arrangement is called network. A network provides the facility for communicating data (UPBoardSolutions.com) and information between different departments in an organization. Computerization of banks is an example of this. Another important advantage of networking is that it allows resources such as a printer, scanner, modem etc. to be shared among all the systems connected to the network.

Computer networks provide many services besides travel reservations and financial transactions, but these applications show two important features of computer networks:

• They provide shared access to information, such as account balances or airline flight status.
• They allow the movement of data, such as flight status updates, or financial transfers.

Advantages of Networking: Networking serves four important purposes:

1. Resource Sharing: It allows departments to share hardware e.g. if there is only one laser printer in a company then networking allows each department’s computer to use this laser printer.
2. Reliability: A file can have copies on two or three different machines, (UPBoardSolutions.com) so if one of them is unavailable (hardware crash), the other copies could be used.
3. Cost factor: A computer network saves time.
4. Communication Medium: Using a network, it is possible for 3 managers, working far apart, to prepare a financial report of the company.

Functions of a Computer Network: A networked computer can do many things which a standalone computer cannot do:

1. Share a single copy of a file among all the users, even simultaneously.
2. Transfer files from computer to computer or from one computer to the shared hard-disk on the server.
3. Share computer resources like printer, all types of disks and drives, modems, fax machines, scanners etc.
4. Share applications even of the entire network, thus, reducing the cost of purchasing. A multi-user license costs much less than buying a standalone license for each user.
5. Use e-mail for internal communications, inter-office notes etc., (UPBoardSolutions.com) creating an almost paperless office.

Components used in a Computer Network: A network is a combination of different components. The most essential components of a single network are:

1. Servers: Servers are the faster computers to run different software/ programs, store and process information and to provide a human interface of the users to be able to use the networked computers.
2. Nodes: Nodes are the computers on the Network which are provided to the users to carry out their tasks using the network.
3. LAN Cable: This is the medium over which the information travels from computer to computer.
4. Network Operating System: It is used to control the movement of information on the network.
5. Network Interface Card: This is used to connect the cables to the computers.

Types of Networks: Networks can be classified as follows:
(1) Local Area Network (LAN): A LAN is a system of interlinked personal computers in a localized area, typically under 1 km across. LANs normally operate within a compact area such as an office building or a campus owned by the using organization. The configuration of a LAN can be a star, a ring or; simple devices attached along a length of cable. In LAN, transmission (UPBoardSolutions.com) channels used are coaxial or fibre optic cable and special interface units rather than telephone lines and modems. Thus, the transmission speed is very high. The attached computers may be of different types and performing a variety of functions such as data processing, word processing and electronic mail.
There are two main advantages of LAN: One is resource sharing and another is communication.
Characteristics of LAN: Following are the characteristics of LAN
Nodes are located in a relatively limited geographic area (less than 15 miles).

1. Owned by a single organization.
2. Usually decentralized control.
3. High data rate.
4. Low error rate.
5. Inexpensive transmission medium (e.g., coaxial).
6. Maintenance is easy.

(2) Wide Area Network (WAN): When the network of computers is spread throughout the country or in the entire world then such a network is called Wide Area Network. Several LANs are connected to form a WAN. WAN provides communication services to a large geographic area (100’s to 1000’s of km). Communication on a WAN takes place via telephone lines, satellite or microwave links, rather than through a physical cable.

ARPANET of the Advanced Research Project Agency of the U.S. Department of Defence is an example of WAN.
Characteristics of WAN: Following are the characteristics of WAN:

1. Nodes are found over a much wider area.
2. Usually used by several different organizations.
3. Often access regulated public or private communication systems.
4. Frequently used for large database access by users over telephone lines.
5. Example – INFONET (Computer Science Corporation).

(3) Metropolitan Area Network (MAN): In between LAN and WAN is the Metropolitan Area Network (MAN). A MAN is a network that covers an entire city but uses LAN technology. Cable television networks (UPBoardSolutions.com) are an example of MANs distributing television signals. The MANs we are interested in, cany information in the form of computer signals from one computer to another.
Characteristics of MAN: Following are the characteristics of MAN

1. Nodes are located in wider areas (generally connects the cities).
2. Owned by big organizations (Government, semi-government or big private organizations).
3. The data rate is slow as compared to LAN.
4. The error rate is high as compared to LAN.
5. Expensive.
6. Maintenance is not easy.

Question 2.
What is the internet? What are its tools or applications? (UP 2004, 06, 09, 11, 12, 13, 16)
Or
Write a short note on ‘Application of the Internet’. (UP 2007, 16)
Or
Describe in brief Internet. (UP 2017)
Answer:
In this age of Information Technology, the Internet is of great importance. Use of the Internet is increasing day by day. Today, the Internet has become a tool of communication.
Internet is an interconnection between millions of computers of different types belonging to various networks all over the globe. It is a network of networks.

Internet is an information highway. You can get any kind of information ranging from movies to sports, politics to streets, science to arts, news and much more. You can talk to a person sitting in any part of the world. It is more popular in youngsters to a chat.
Internet means different things to different people. It is:

• a global community of computer users.
• an enormous library of information.
• a vast communication network.
• a way to store a common body of knowledge.
• fun to visit.

Application of Internet: Application of the Internet is the following:
1. E-mail: The most commonly used facility of the Internet is E-mail. Users can get E-mail account by signing on websites providing free E-mail facility, e.g., indiatimes.com, hotmail.com, yahoo.com, rediff.com etc. or paid (UPBoardSolutions.com) facility. With a message, we can attach a greeting card or a useful document. Hotmail (www.hotmail. com) is the first company to start E-mail service for business. It was developed by an NRI Sabeer Bhatia. After its great success, Microsoft bought it for 7 million dollars.

2. Telenet: Using this facility, one can use another computer connected to the Internet, even while sitting at home and can use the resources available at that end. This facility is widely used by research institutions to connect to the supercomputer to use their processing power for scientific researches, weather forecasting.

3. File transfer facility: One can copy the files from different computer users connected by using telnet. We have a set of utility software, which helps us to find the computers to which computers are connected to like Archie, Gopher, Veronika etc. They keep track of the information stored on various computer parts of the Internet.

4. WWW: World Wide Web is a section of the Internet, where related files are interlinked. This facility is similar to a magazine which consists of web ‘sites’ (Topics) and web pages through which one can get information about different topics.

5. FTP: File transfer protocol transfers the file from one location to another location.

6. URL: Uniform resource locator is a tool, which helps you to locate the files you want.

7. Gopher: This is the Internet tool which makes it easy to get the information from different libraries and servers.

8. E-commerce: It is the facility of doing business through the Internet. E-commerce is helpful in doing business worldwide while sitting in remote locations. Now, by using E-commerce facilities, one can transfer money faster, order goods and generate more information about products faster. It is the platform for buyers and sellers.

Question 3.
What is Network Topology? What are the different types of network topology? (U. P. 2007, 19)
Answer:
Meaning of Network Topology: The topology of a network is the structure defined by the interconnection scheme. This structure can be viewed as a graph with vertices representing the switching nodes and the branches representing the transmission channels. The choice of topology involves many interrelated factors:

1. Expected traffic.
2. Routing method.
3. Channel capacity.
4. Cost.

Types of Network Topology: The various topologies are

1. Mesh Topology
2. Ring Topology
3. Bus Topology
4. Tree Topology
5. Star Topology.

1. Mesh Topology: In this type of structure, each node is directly connected to every other node. Each device has a point-to-point link with each other device. This topology provides alternative routes between nodes. A very (UPBoardSolutions.com) large wire length is required and cost may become too high to be justified. Public and private data communication networks use this kind of topology. It is also known as fully connected topology.

2. Ring Topology: In this topology, the host computer and workstation are connected in series forming a complete ring for data communication. The links are unidirectional (clockwise/anticlockwise). It is economical and no collision of data takes place between two workstations. The problem arises while adding new devices in the networking series. It is used in LANs.

3. Bus Topology: In this kind of structure, there is no central host computer. There is a single data cable which is shared by the workstations. It allows flexible networking as devices can be easily attached. It is economical because the single cable is involved but the possibility of data collision occurs.

4. Tree Topology: It is also known as hierarchical or vertical network. There may be more than one central nodes as it follows tree-like architecture. If one centre fails, the network can continue to be partially operational. This kind (UPBoardSolutions.com) of structure is used in remote access networks.

5. Star Topology: In this, different workstations are connected by cables with the centrally located host computer known as server or HUB. The server is responsible for routing traffic and fault isolation. The failure of workstation does not affect structure, but a failure of the centrally located host computer, HUB causes a complete breakdown of the communication network.

Question 4.
Differentiate between LAN and WAN. (UP 2008, 14)
Or
Compare LAN and WAN. (UP 2007, 16)
Answer:
The main differences between LAN and WAN are:
1. A LAN is restricted to the limited geographical coverage of a few kilometres but a WAN can be spread throughout the country or the entire world.

2. The cost of transmitting data in LAN is negligible since the transmission medium is usually owned by the user organization. However, in the case of WAN, this cost may be very high because the transmission medium used are leased lines or public systems such as telephone lines, microwaves and satellite links.

3. In LAN, the computers, terminals and peripheral devices are physically connected with wires and coaxial cables. Whereas, in WAN, there may not be a direct connection between various computers.

4. Data transmission speed is much higher in LAN as compared to WAN. Transmission speed in LANs is 0.1 to 100 megabits per second. On the other hand, in WAN, the data transmission speed is normally of the order of 1800 to 9600 bits per second.
LANs are less error-prone as compared to WANs. Since in a LAN, distance covered by data is limited, less error occurs in LAN.

Question 5.
What is www? What is ‘web-server’? What are web pages? (UP 2005, 10, 17)
Answer:
www (world wide web) is a section of the internet where related files are interlinked. This facility is similar to a magazine which consists of web sites and web pages through which one can get information about different topics, www is a vast ocean of information. Information regarding almost every topic, place, country, etc. is available on it. Actually, the information about different (UPBoardSolutions.com) topics and places is stored on bigger and efficient computers which provide this information to other connected computers. These computers with better efficiency are called ‘web-servers’. Almost every country has its own web-server which stores the information about that country and these servers are connected to each other to share their information and provide it to the other connected computers.

The page on which information is written on www is called web pages. These web pages are designed by skilled web designers and then launched on www. The collection of web pages related to someplace or topic is called web site. There are different types of sites available on www like:

• .com – commercial sites
• .edu – educational sites
• .mil – military sites, etc.
• .gov – government sites
• .net – networking sites

There are different search engines available on the Internet which work as an interface between www and internet user because they are helpful in searching the sites related to any topic.

Network: LAN and WAN Short Answer Type Questions (4 Marks)

Question 1.
What do you mean by the server?
Answer:
Servers are the faster computers to run different software/ programs, store and process information and to provide a human interface of the users to be able to use the networked computers. They are of two types:

1. Dedicated Server: It makes the information available for other computers of the network.
2. Non-dedicated Server: It works as both service provider as well as the client.

Question 2.
What do you mean by Letter Addressing System?
Answer:
Letter Addressing System. An example of a letter address is www.microsoft.com. which is the website of Microsoft Corporation? Last three letters of an address are of extension, which indicates the kind of service provided by that domain. Following table shows a list of most commonly used extensions.

Abbreviation	Representation
.edu	Educational institutions
.mil	Military sites
.gov	Government departments
.net	Networking organizations
.com	Commercial organizations
.int	International organizations
.org	Non-profit organizations

The letters addressing system also uses country codes comprising two letters. Examples of country codes are .in for India, .ca for Canada, .au for Australia. This letter addressing system is also called the Domain Naming System (DNS).

Question 3.
What are the advantages of the Internet? (UP 2008, 10, 12, 15)
Answer:
Internet is an Information Highway and it has enormous advantages, few of them are as follows:

1. Information can be transferred from one place to another.
2. One can talk to a person sitting in any part’ of the world.
3. Lots of facilities available for (UPBoardSolutions.com) entertainment like games, movies, online programs, etc.
4. One can do business on the internet and this facility is known as E-commerce.
5. One can get information on any topic regarding education.
6. One can search for a job.
7. Marriages can be settled through the internet.
8. It is a great time and money saver.
9. One can maintain his bank account through the internet
10. Billings and reservations can be done using the internet.
11. News, live matches, concerts, etc. can be seen through the internet.

Question 4.
Differentiate between Protocol and Topology. (UP 2014)
Answer:
Difference between Protocol and Topology

Protocol	Topology
1. These are some set of rules, regulations and guideline.	1. The topology of a network is a structure defined by the interconnection scheme.
2. It is a smooth network to communicate.	2. It is not smooth network to communicate.

Question 5.
What is a Bus Topology? Explain its advantages and disadvantages.
Answer:
Bus Topology: BUS Topology consists of a common channel over which data packets can be transmitted, either to a specific destination or in the broadcast mode. It allows flexible networking as devices can be easily attached. It is economical because a single cable is involved.
Advantages: There are the following advantages of Bus Topology:

• New nodes can be added easily, and all nodes can communicate directly with any other node on the bus.
• Data packets from one station can be received by all other stations.

Disadvantages: There are the following disadvantages of Bus Topology:

• Since all the stations share the channel, only one station can transmit at any one time.
• Possibility of data collision.

Network: LAN and WAN Very Short Answer Type Questions (2 Marks)

Question 1.
Write an example of LAN?
Answer:
ARPANET is an example of a LAN.

Question 2.
In which topology, all workstations are connected to a central computer? (UP 2016)
Answer:
In star topology, all workstations are connected to a central computer.

Question 3.
What is the login process? (UP 2014)
Answer:
The logging process is used to track what action the user has taken while connected to the site.

Question 4.
Discuss Search Engines. (UP 2014)
Answer:
It is a facility which allows us to navigate various (UPBoardSolutions.com) sites available on www by simply stating its name.

Question 5.
What is the data transmission speed of WAN?
Answer:
The data transmission speed of WAN is 1800 to 9600 bits per second.

Question 6.
Name the network developed for interlinking U.S. scientific and academic researches.
Answer:
ARPANET.

Question 7.
Name the device which provides information through Internet services.
Answer:
Server/Host Computer.

Question 8.
Which service is used to locate files that are publicly accessible by FTP?
Answer:
Archie.

Question 9.
Draw figure of Ring Topology? (UP 2017)
Answer:

Question 10.
Which language is used in designing the web page? (UP 2017)
Answer:
HTML.

Network: LAN and WAN Objective Type Questions (1 Marks)

There are four alternative answers for each part of the questions. Select the correct one and write in your answer book:

Question 1.
SNA was the first computer network developed by:
(a) IBM
(b) HCL
(c) CMC
(d) None of these.
Answer:
(a) IBM

Question 2.
Peer to Peer Network found in offices and schools is also known as :
(a) Server Network
(b) Workgroup Network
(c) Hybrid Network
(d) None of these.
Answer:
(b) Workgroup Network

Question 3.
Communication on a WAN takes place via (UP 2014)
(a) Satellite
(b) Microwave links
(c) Telephone
(d) All of the above.
Answer:
(d) All of the above.

Question 4.
In which topology, HUB is used:
(a) Internet
(b) Star topology
(c) Ring topology
(d) Bus topology.
Answer:
(b) Star topology

Question 5.
Which topology is restricted to building office:
(a) LAN
(b) MAN
(c) WAN
(d) BUS.
Answer:
(a) LAN

Question 6.
In which communication network, the satellite is used:
(a) LAN
(b) MAN
(c) WAN
(d) Internet
Answer:
(c) WAN

Question 7.
Indonet is developed by:
(a) IBM
(b) CMC
(c) HCL
(d) None of these.
Answer:
(b) CMC

Question 8.
Through computer network we can share:
(a) Hardware resources
(b) Software application
(c) Printer
(d) All the above.
Answer:
(d) All the above.

Question 9.
A link that takes you to a different part of the same page:
(a) URL
(b) Anchor
(c) Hyperlink
(d) Quicklink.
Answer:
(b) Anchor

Question 10.
Who governs the Internet as a whole?
(a) USA
(b) Australia
(c) India
(d) None of these.
Answer:
(d) None of these.

Question 11.
Which software do you need to access www?
(a) Gopher
(b) Archie
(c) Winsock
(d) Browser.
Answer:
(d) Browser.

Question 12.
What is a Web Browser? (UP 2017)
(a) Memory card
(b) Software program
(c) Modem
(d) Compiler.
Answer:
(b) Software program

Question 13.
On which topology is the satellite transmission based. (UP 2017)
(a) Ring
(b) Bus
(c) Star
(d) Tree.
Answer:
(c) Star

UP Board Solutions for Class 10 Computer Science

UP Board Solutions for Class 10 Computer Science Chapter 8 Subscripted Variables

Subscripted Variables Long Answer Type Questions (8 Marks)

Question 1.
What are subscripted variables? What is an Array? Explain. (UP 2007, 19)
Or
What is an Array? What are its different types? Explain. (UP 2009, 12)
Or
Explain the subscripted variable. (UP 2017)
Answer:
Subscript: A subscript may be a numeric constant or an integer-valued variable, is enclosed in parenthesis which identifies the position of a given element in the array. For example, the first element of (UPBoardSolutions.com) array stu_age (containing the value 14) is referred to as stu_age [0].
Similarly,
stu_age [1] = 16
stu_age [2] = 18
stu_age [3] = 17
stu_age [4] = 15
Here, 0, 1, 2, 3, 4 within parenthesis are known as subscript. In ‘C’ first element is in the Oth place and last element in the (n -l)th place in the array of n elements.

Subscripted Variable: A variable with a subscript is known as subscripted variable and it refers to one value in the array, e.g., stu_age [0], stu_age [1], etc.
Declaration of an Array: As you know that all variables in ‘C’ must be declared before use, hence, we must declare the array. It is done at the beginning of the function main () with data type and size.
Syntax:
datatype name [size];
Example:
int stu_age [5];

This statement states that stu_age is an array of 5 integers (Number of elements). This statement reserves enough memory for stu_age to hole 5 integers. Once the declaration is made, stu_age [0] refers to the first integer in (UPBoardSolutions.com) the array, stu_age [1] refers to the second integer in the array and so on.

Question 2.
(a) Explain the following with reference to ‘C’ language: (U. P. 2006)
(i) Data Type
(ii) Variables.
(b) What are the various arithmetic operators available in ‘C’ language? Explain with example.
Answer:
(a) (i) Data Type: A data type decides the amount of memory to be allocated to a variable to store a particular type of data. To allocate memory for a particular piece of data, we have to declare a variable of a particular data type. The variable declaration means that some memory is allocated and that portion of memory will be referred to by the variable name.
Data types, which are commonly used in programming tools can be classified as :

• Numeric: Stores numeric value.
• Alpha Numeric: Stores descriptive information.

A numeric data type is called int: Similarly, an alpha-numeric data type is named char in C.

(ii) Variables: A variable is a name that represents a number or a string. Each numeric variable must consist of a letter or a letter followed by an integer. All variables that are to be used in the program must be declared prior to its use. Declaring a variable means defining a name and a data type of a variable. Every variable declaration is terminated by a semicolon. Variable (UPBoardSolutions.com) names must begin with an alphabet. The first character may be followed by a sequence of letters or digits and can also include the special character ‘Underscore’.

(b) Arithmetical Operators: Operators that perform mathematical operations are called Arithmetical operators. These operators form a mathematical expression using operands along- with. There are five types of arithmetical operands available in C++ which are as follows:
(i) Add (+): To perform addition of operands. These operands can either be literal, identifier or combination of both.
e.g.:
a + b
2 + 2
x + 2

(ii) Subtract (-): In order to perform subtraction, operands can be literal, identifier or combination of both.
e.g.:
x – y
15 – 5
A – 10

(iii) Multiply (*): This operator performs multiplication on operands.
e.g.:
y * z
15 * 32
A * 25

(iv) Divide (/): It is used to perform division of the two operands.
e.g.
A/B
25/5
X/2

(v) Exponentiation (%): It is a modulus operator and returns the remainder of the division. A / operator returns the quotient after the division of operands and a modulus operator returns the remainder after division.
e.g.
10 % 3
X % 2

Question 3.
What do you mean by sorting? Define two methods of sorting. (UP 2004, 05, 11)
Or
Give names of the main methods of sorting and explain any one method with an example. (UP 2014, 15)
Answer:
Sorting: Sorting is the process of arranging the data or information in (UPBoardSolutions.com) some logical order. This logical order may be ascending or descending in case of numeric values or dictionary order in case of alphanumeric values.
For example: Suppose an unsorted array X of ten numeric values.

There are some methods of sorting the data of an array.

1. Insertion sorting
2. Bubble sorting
3. Selection sorting.

Insertion Sorting: This process uses only one array and requires (N – 1) passes and total comparison required are N (N – l)/2 to sort this array. The processing of sorting in ascending order is as follows:
Suppose an unsorted array A is

This array has 6 elements, so it will complete the sorting in 5 passes (N – 1 ⇒ 6 – 1 = 5)

In this pass, the first element of an array should be compared with the rest of the array elements and placed the smallest element on top in ascending order.

Suppose an unsorted array A is

Now you will sort this array using bubble sort method. In this method also, (UPBoardSolutions.com) sorting requires (N – 1) passes to sort the elements of the array.

Question 4.
What is searching? Explain its mechanism. (UP 2007, 11, 15)
Or
What is searching? Explain two searching techniques. (UP 2009, 15)
Answer:
Searching: It refers to the process of finding the location of the given data element from a collection of data. The search is said to be successful if the given data element is found.
There are two searching techniques :

1. Linear Search
2. Binary Search.

1. Linear Search: It is also known as sequential search. In sequential searching, a particular data item is searched sequentially, Le., the desired data first compared with the first element then the second element of an array, (UPBoardSolutions.com) and so on.
Example: WAP in ‘C’ to find the given number in the given array of 10 numeric type values:
Program :

# include<stdio.h>
void main()
{
int A [10] = {10, 50, 6, 7, 20, 30, 15, 25, 80, 90},
int i, N;
printf (“Input the Number”);
scanf(“%d”, &N);
for (i = 0; i < 10; i ++)
{
if (N = = A[i])
printf (“%d is present in list on %d position”, N, i);
break;
}
printf (“N is not present”);
}

2. Binary Search: In binary searching, the arranged data is divided into two parts. The particular data item to be searched is compared with the middle data item. If it is less than the middle data, then it means that the data item to be searched is present in the first half of the data item set. The loop will be created for only half of the total value, thus, it saves the computer time also. In a binary search, it is mandatory that the data be arranged in either ascending or descending order.
Example: Given a sorted (ascending order) array A with elements and we want to search the element 15 in it by binary search.

Binary Search Method:
Given Array A

To start with, we take BEG = 0, END = 6, and compute location of the middle element as MID = (BEG + END)/2 = (0 + 6)/2 = 3.

Since, A[MID] le., A[3] ≠ 15, and BEG < END. We start next iteration. As A[MID] = 20 > 15, therefore, we take END = MID -1=3-1=2, where BEG remains unchanged.
MID = (BEG + END)/2 = (0 + 2)/2 = 1
Since, A[MID] le., A[1] ≠ 15, and BEG < END.
We start the next iteration.
As A[MID] = 10 < 15, therefore, we take BEG = MID + 1 = 1 + 1 = 2, where END remains unchanged; since BEG = END, again compute location of the middle element as
MID = (BEG + END)/2 = (2 + 2)/2 = 2
Since A[MID] le., A[2] = 15, the search terminates with success.

Question 5.
What do you mean by Array? Define different types of array. (UP 2008, 12, 15, 19)
Or
What do you understand by Array? What are its different types? Describe each of them. (UP 2011)
Or
What do you understand by Array? Discuss one dimensional and two-dimensional array with example. (UP 2017)
Answer:
An array is the collection of numeric or string values in the form of LIST (single row) or TABLE (rectangular arrangements in the form of rows and columns). A single variable name is used to refer to the entire collection of (UPBoardSolutions.com) items. ‘C’ language permits us to deal with many related data items as a group by means of the structure known as an array.

An array can be used to store integer, real or string values, but the values in a given array must be of the same type. That is, if an array is given a numeric variable name, a string data item cannot be entered to it, only numeric values are allowed. For example, suppose that there are five test scores 15, 25, 35, 81, 75 to be stored. The scores could be put in an array called TEST. This array can be represented in memory as such.

There are two types of array.
1. Single-dimensional array: It is a collection of numeric or string values in the form of a list. This is also known as single subscript variables because these variables have one subscript only e.g. int a[10].

2. Multi-dimensional array: It is defined in the same manner as a single-dimensional array, except that a separate pair of square brackets are required for each subscript. It is the collection of numeric or string values in the form of TABLE
e.g. A[5][6], B[2][3][2] etc.

Question 6.
WAP to sort the elements of an array in ascending order. (UP 2006)
Answer:

#include<stdio.h>
void main()
{
int A[100];
int n, i, j, temp;
printf (“Enter how many nos”);
scant (“%d”, &n);
for (i = 0; i < n; i++)
{
scanf (“%d”, &A[i]);
}
for (i =0; i < n - 1; i++)
{
for (j = 0; j < n + i; j++)
{
if (A [j +1] < A[j])
temp = A[j];
A[j] =A[j + 1];
A[j + 1] = temp;
}}
for (i = 0; i < n; i++)
{
printf (“%d”, A[i]);
}
}

Question 7.
WAP to search the given number in the given array of 10 numeric type values:
Answer:

#include<stdio.h>
void main ()
{
int A[10] = {10, 50, 20, 30, 6, 7, 8, 70, 90, 75};
int i, n;
printf (“input the number”);
scanf (“%d”, &n);
for (i = 0; i < 10; i++)
{
if (n == A[i])
printf (“%d is present in list on %d position”, n, i);
break;
}
printf (“%d is not present”, n)
}

Subscripted Variables Short Answer Type Questions (4 Marks)

Question 1.
What do you mean by subscript? (UP 2012)
Answer:
To gain access to a single element within the array, a subscript is used. A subscript may be a numeric constant or an integer-valued variable, is enclosed in parentheses which identify the position of a given element in the array. (UPBoardSolutions.com) For example, the first element of array TEST (containing the value 15) is referred to as TEST(0J. The second test score is as TEST[1], the third test score is as TEST[2], and so on. Therefore, the following statements are true:
TEST[0] = 15
TEST[1] = 25
TEST[2] = 5
TEST[3] = 81
TEST[4] = 75
Here, 0, 1, 2, 3 and 4 within parentheses are known as a subscript.

Question 2.
Define the term List and Table.
Answer:
An array is a collection of numeric or string values in the form of LIST or TABLE.
LIST: List is a kind of arrangement in which values are arranged either in horizontal form or vertical form in a sequential row.
e.g.,

TABLE: Table is a rectangular arrangement of values in the form of rows and columns.
e.g.,

Question 3.
WAP to find the factorial of ‘n’.
Answer:

#include<stdio.h>
void main()
{
int n, i, fact = 1;
printf (“Enter the value for n”);
scanf (“%d”, &n);
for (i = 1; i <= n; i++)
{
fact = fact * i;
}
printf (“factorial of %d is %d”, n, fact);
}

Question 4.
What is Binary Search? (UP 2011, 19)
Answer:
In this method of searching, only sorted data can be used. Unsorted data cannot be used to apply this type of search. To do searching in Binary method, the sorted data is divided into two parts and the particular element is compared (UPBoardSolutions.com) with the middle element. If found greater, the first and middle element is divided into two parts and their middle element is compared. And if found smaller, the middle and the last element is divided into two parts and their middle element is compared. This process goes on until the search is completed. This method of search is quick and saves time. It is also known as Random search.

Question 5.
Write a short note on sorting? (UP 2008, 11, 12)
Answer:
It is easy to carry out different operations on the idea if it is arranged or in some order (ascending or descending). The process of arranging the data or information in some order (ascending or descending in case of numeric data and dictionary order in case of alphanumeric data) is called sorting.
Example:

Question 6.
Write a short note on searching? (UP 2008)
Or
Differentiate between sequential and binary search. (UP 2014)
Answer:
Searching: Searching means finding an element from an array. It refers to the process of finding the location of a given data element from an array. For example: If you want to work on your computer notebook, you have to search for it for yourself. You can do searching by two methods:

1. Sequential Search: This search is also known as linear search because in this method to search an element from data source one has to compare particular data item with the first element than the second element and so on until the search is completed. Because of this sequential approach, it is known as sequential search. In this, if the element is found in the middle, search process terminates.

2. Binary Search: In this method of searching, only sorted data can be used, unsorted data cannot be used to apply this type of search. To do searching in Binary method, the sorted data is divided into two parts and the particular element is (UPBoardSolutions.com) compared with the middle element. If found greater, the first and that middle element is divided into two parts and their middle element is compared. And if found smaller, the middle and the last element is divided into two parts and their middle element is compared. This process goes on until the search is completed. This method of search is quick and saves time. It is also known as Random search.

Subscripted Variables Very Short Answer Type Questions (2 Marks)

Question 1.
From which element binary search starts searching in an array?
Answer:
From the middle element, the binary search starts searching in an array.

Question 2.
What do you mean by sorting? (UP 2012)
Answer:
Sorting is the process of arranging the data in some order.

Question 3.
Is an array a collection of similar elements?
Answer:
Yes, an array is a collection of similar elements.

Question 4.
What is the number of the first element in an array?
Answer:
The first element in the array is (UPBoardSolutions.com) numbered 0.

Question 5.
What are the different methods of sorting?
Answer:
The different methods of sorting are:

1. Insertion
2. Bubble
3. Selection.

Question 6.
Arranging the data in some order is known as:
Answer:
Sorting.

Question 7.
Name two types of searching.
Answer:
Sequential and Binary.

Subscripted Variables Objective Type Questions (1 Marks)

There are four alternative answers for each part of the questions. Select the correct one and write in your answer book:

Question 1.
A double dimensional array is a collection of a numeric value in the form of:
(a) TABLE
(b) WAP
(c) SORT
(d) None of these.
Answer:
(a) TABLE

Question 2.
Which of the following is not a character constant?
(a) Sorry
(b) Enter values of A, B, C.
(c) 123.50
(d) All of the above.
Answer:
(d) All of the above.

Question 3.
If x is an integer variable, x = will return a value:
(a) 2.5
(b) 3
(c) 2
(d) 1
Answer:
(b) 3

Question 4.
The maximum width of a ‘C’ variable name can be:
(a) 5 characters
(b) 8 characters
(c) 10 characters
(d) 20 characters.
Answer:
(b) 8 characters

UP Board Solutions for Class 10 Computer Science

UP Board Solutions for Class 10 Computer Science Chapter 2 Modes of Transmission

Modes of Transmission Long Answer Type Questions (8 Marks)

Question 1.
What are the different transmission modes? (UP 2004, 16)
Or
What is simplex and duplex modes of transmission? (UP 2006, 07)
Or
Explain ‘Simplex’ and ‘Duplex’ system. Why is the duplex system more popular? (UP 2011, 12)
Or
Describe in brief duplex. (UP 2016)
Or
What is Simplex Communication? (UP 2018)
Answer:
Data Transmission Modes: The term ‘transmission mode’ is used to define the direction of signal flow between two linked devices.
There are three ways or modes for transmitting data from one point to another. These are:

1. Simplex
2. Half-duplex
3. Full-duplex.

1. Simplex: If the transmission is simplex, communication can take place in only one direction. Devices connected to such a circuit is either a send-only or a receive-only device. For example, broadcasting (UPBoardSolutions.com) of signals to the television. In this case, TV can receive signals only, it cannot send back signals to satellite or any other device.

In data processing applications, communication in both directions is required. Even for a ‘one-way’ flow of information from a terminal to a computer, acknowledgement from the terminal to the computer is required. Thus, simplex circuits are seldom used in data communication.

2. Half-duplex: Signals can be transmitted from both sides but hot at a time. In half-duplex transmission, you can transmit signals in both directions, but not simultaneously. If the communication line is busy, then the message will be in a wait state. The buffer transmits that signal first, which is accepted first. Example of this kind of transmission is E-mail. When we send a message from (UPBoardSolutions.com) our inbox to an E-mail address then the following message appears:
Your message has been sent to the following recipient: chan- dress-5 @ Indiatimes. com.
This is an acknowledgement, confirming that the message has reached to its recipient.

3. Full-duplex: Some applications require simultaneous transmission in both directions. In such cases, a full-duplex system is used that allows information to flow simultaneously in both directions on the transmission path. Examples of these transmission techniques are telephone system and signal transmission between different computer hardware devices.
One common example of full-duplex communication is the telephone network. When two people are communicating by a telephone line, both can talk and listen at the same time.

Question 2.
Write about different communication channels?
Answer:
The communication data transfer rate is measured in bits per second (bps) or band, depending on their transmission speed. Communication channels (paths) are grouped into three basic categories: narrowband, voiceband and broadband.
Narrowband: When the data transfer rate is between 45 to 300 bps then this is called Narrowband transmission. They are used mainly for telegraph lines and low-speed terminals.

Voiceband: Voiceband channels handle moderate data volumes and can transmit data at speed up to 9600 bps. They are so-called because their major application is for ordinary telephone voice communication. Most remote terminals are connected to computers through voiceband channels.

Broadband: Broadband or wideband channels are used when a large volume (UPBoardSolutions.com) of data is to be transmitted at high speed. These systems provide data transmission rates of 1 million (106) bps or more. Nowadays, broadband communication is gaining popularity. This is basically used in mobile devices such as cellular phone, laptop, notebook etc.

Question 3.
Explain the following: (UP 2004)
(a) Analogue transmission
(b) Digital transmission.
Answer:
Data is propagated from one point to another by means of electrical signals which can be of two forms:

1. Analogue signals, and
2. Digital signals.

In the analog signal, the transmitted power varies over a communication range as in sound, light and radio waves.

Digital signals are coded representation of information. Keyboard characters, for example, are usually encoded in binary digit code.
The digital signal is a sequence of voltage pulses represented in binary form.
Computer-generated data is digital whereas telephone lines used for data communication in computer networks are usually meant for carrying analogue signals. When digital data are to be sent over an analogue facility, the (UPBoardSolutions.com) digital signals must be connected to analogue form. This is usually done by using a device called modem that is capable of connecting a digital signal to analogue and vice-versa.

Question 4.
What is meant by wired and wireless communication system? List their advantages and disadvantages. (U. P. 2007)
Answer:
The medium is the matter or substance that carries the voice or data transmission. It can be copper, glass, or wave. A circuit is nothing more than the path over which data moves. Communication media is of two types:
(A) Wired Media: In this type of media, wires are used. It is further classified into three categories:
1. Twisted Pair Cable: Twisted pair of wires is the main media used in local telephone communication and short distance (less than 1 km) digital data transmission. Pairs of wire are twisted together to reduce interference by adjacent wires. Wires are usually made of copper. This medium is inexpensive.
The main advantages of twisted pair cable are its simplicity and ease of installation. It is physically flexible, has a low weight and can be easily connected.

The twisted pair is used for audio telephone communication with speech signal bandwidth of 4 kHz. (UPBoardSolutions.com) However, it has much higher bandwidth of about 50 kHz. The speed of digital signal transmission using telephone lines is 1200 bps (bits per second) (Also commonly quoted as 1200 bands).

Twisted pairs are used to connect terminals to the main computer. In this case, the speed of transmission is up to 9.6 kbps, if the length is less than 100 metres. Noise pick up by twisted wire which results in high error rates when the line length is more than 100 metres. This limits the use of twisted pair.

2. Coaxial Cable: Coaxial cables are groups of specially wrapped and insulated wire lines that are able to transmit data at high rates. They consist of a central copper wire surrounded by a PVC insulation over which a sleeve of copper mesh is placed. The metal sleeve is again shielded by an outer shield of thick PVC material. The signal is transmitted by the inner copper wire and is electrically shielded by the outer metal sleeve.

Coaxial cables offer much higher bandwidth and are capable of transmitting digital signals at a very high rate of 10 Mbps. They are extensively used in long-distance telephone lines and cable TVs. They can handle 15,000 telephone calls simultaneously. Coaxial cables have much higher noise immunity and can offer data transmission without distortion or loss of signal.

3. Fibre Optic Cable: Physically, an optical fibre consists of a glass core, a plastic or glass (UPBoardSolutions.com) cladding and a protective coating. The ore diameter is between 8 and 200 micrometres. Optical fibres have several advantages. They are:

• Very high bandwidth.
• Protection against electromagnetic interference.
• More secure as they cannot be tapped easily.
• Lightweight and no corrosion.

The major disadvantages of fibre optic cables are:

• It is difficult to align and join two fibres in the field without using special equipment.
• They are fragile and cannot have sharp bends.

In fibre optic communications, electrical signals are transformed into light pulses by a modulator, transmitted over the fibre as light waves, detected and converted back to electrical signals by photoelectric diodes.

(B) Wireless Media: In this type of media, wires are not used, hence, there is no physical connection. It is further classified into two categories:
1. Microwave: Parabolic antennas are mounted on towers to send beams. It is cheaper than digging trenches for laying cables, and maintaining repeaters of cables if cables get broken by a variety of causes. Transmitter and receiver must be in the line of sight—30 miles apart because of earth curvature, possible interference from the environment, lack of security, high initial equipment cost. Relatively high-speed data rates up to 250 Mbps.
Usage: Voice Communication (Cellular Services).

2. Satellite: There is a need of 12 to 24 transponders per satellite. These transponders receive, amplify, change frequency and transmit. Geosynchronous orbit (22,300 miles) Low security-anyone with satellite dish and right frequency can tune in. Ease of adding stations. Data rates up to 50 Mbps. Microwave signal at 6 GHz is beamed to it from a transmitter on the earth. It is amplified and (UPBoardSolutions.com) retransmitted to the earth at 4 GHz by a system called transponder mounted on the satellite to avoid interference.

Question 5.
What is meant by Protocol? What protocols are used on the internet? Explain. (UP 2008)
Or
What is the Protocol? Why is it needed in networks? Explain. (UP 2011)
Or
Write in brief Protocol. (UP 2017)
Answer:
Protocol: Protocol is a software, i.e., set of rules which are used to establish communication between several computers. It defines the exact order in which two machines exchange data with one another. Protocols are technical customs or guidelines that govern the exchange of signal transmission and reception between equipment. Each protocol specifies the exact order in which signals will be transferred. Both Hardware and software are designed to handle specific protocols.
Functions of Protocol: There are the following functions of protocol:

• How to begin and terminate a session between two computers?
• How the messages in a session are to be framed?
• How errors in the transmission of messages are to be detected?
• How messages are to be retransmitted when errors are detected?
• How to find out which message block was sent by which terminal computer and to whom?
• How the dialogue on the communication line proceeds?

Examples:

1. TCP/IP (Transmission Control Protocol/Internet Protocol): TCP breaks up the data to be sent into packets. It guarantees that any data sent to the destination computer reaches it. IP is a set of conventions used to send (UPBoardSolutions.com) packets from one host to another. It is responsible for routing the packets to a desired destination IP address.
2. X.12: This protocol is used to establish a connection between companies to exchange important papers.
3. X. 25: This protocol establishes the interface for common data network.
4. HTTP: HyperText Transfer Protocol works on the internet to send or receive files from different locations.

Modes of Transmission Short Answer Type Questions (4 Marks)

Question 1.
What do you mean by bandwidth? (UP 2008, 18)
Answer:
A term used to describe the data-handling capacity of a communication system is bandwidth. Bandwidth is the range of frequencies that is available for the transmission of data. A narrow range of frequencies in a communication system is analogous to a narrow road, i.e., its data transfer rate is limited, just like the flow of traffic on a narrow road. Wider bandwidth permits more data transfer through the communication channel at the same time.

Question 2.
What is data transmission speed? (UP 2016, 19)
Answer:
In computer communication, the amount of data transferred from one place to another in one second is known as data transmission speed. It is measured in bps (bits per second) kbps (kilobytes per second), Mbps, etc. (UPBoardSolutions.com) There are three communication channels on the basis of data transmission speed:

• Narrowband transmission – 45 to 300 bps
• Voice band transmission – up to 9600 bps
• Broadband transmission – 106 bps or more

Question 3.
What is a MODEM? (UP 2008, 12, 15, 18)
Answer:
A modem is a device which is used to connect a computer to a telephone line for the purpose of transmission. It is because of a modem, your PC can be connected to the internet through a telephone line. The computer is a digital device and it works on digital signals whereas the telephone is an analogue device and works on analogue signals. At both the ends, computers are connected to telephone lines through modem because it is modem which converts digital signals to analogue and again back to digital signals at receiving end. The process of converting digital signals to analogue signals is called Modulation and the process of converting analogue signals to digital is known as Demodulation,
(Modem = Modulation + De = Modulation)

The speed of transmission is measured in bps. Modems usually operate at speeds ranging from 2,400 to 28,800 bits per second over standard telephone lines, and at faster rates over leased lines. A suitable communication program is needed to operate the modem.

Question 4.
Write the type of connections. (UP 2017)
Answer:
There are three types of connections:
1. Dial-up connections: This is a kind of connection which is available through telephone lines. Through this, we can connect to the local exchange and for this, we have to dial a number. After the establishment of the connection, (UPBoardSolutions.com) we can transfer information. This service is also known as switching service and its bandwidth is less than 400 Hz.

2. Leased-Lines: This service provides user 24-hour connection. This connection is also available through telephone lines but through switches. This is uninterrupted service.

3. Integrated Service Digital Network (ISDN): This service is totally dedicated to the computer because separate lines are used for the purpose of transmission. Mostly co-axial cable is used for this. In this digital transmission, media is used and one can send voice, data etc. through this connection.

Modes of Transmission Very Short Answer Type Questions (2 Marks)

Question 1.
What is the full form of MODEM? (UP 2015)
Answer:
Modulation and Demodulation.

Question 2.
Which type of signals travels over telephone lines?
Answer:
Analogue signals.

Question 3.
Which transmission channel has the highest bandwidth?
Answer:
Broadband channel.

Question 4.
What is the data transfer rate of Narrowband Channel?
Answer:
300 to 9600 bps.

Question 5.
In which mode, communication is unidirectional?
Answer:
Simplex Mode.

Question 6.
In which type of transmission, collection of 8 wires is needed to transmit 8 bits? (UP 2008, 11)
Answer:
Parallel transmission.

Modes of Transmission Objective Type Questions (1 Mark)

There are four alternative answers for each part of the questions. Select the correct one and write in your answer book:

Question 1.
E-mail is an example of:
(a) Network
(b) Simplex
(c) Duplex
(d) Half-duplex.
Answer:
(d) Half-duplex.

Question 2.
Converting digital signal into an analog signal is known as:
(a) Modem
(b) Modulation
(c) De-modulation
(d) Transmission.
Answer:
(b) Modulation

Question 3.
The process of converting an analog signal into digital is known as:
(a) Modulation
(b) De-modulation
(c) Analog Transmission
(d) Digital Transmission.
Answer:
(b) De-modulation

Question 4.
The data handling capacity of a communication system is known as:
(a) Bandwidth
(b) Narrow Band
(c) Voice Band
(d) BroadBand.
Answer:
(a) Bandwidth

Question 5.
T.V. is an example of:
(a) Simplex Mode of transmission
(b) Half-duplex Mode of transmission
(c) Full-duplex Mode
(d) None of these.
Answer:
(d) None of these.

Question 6.
Which one of the following is not a protocol?
(a) TCP/IP
(b) ISP
(c) HTTP
(d) X.25.
Answer:
(b) ISP

Question 7.
Telephone lines carry which type of signals:
(a) Analog
(b) Digital
(c) Hybrid
(d) None of these.
Answer:
(a) Analog

Question 8.
Bits are transferred sequentially one by one in:
(a) Parallel Transmission
(b) Analog Transmission
(c) Serial Transmission
(d) None of these.
Answer:
(c) Serial Transmission

Question 9.
Which connection is available through telephone liens?
(a) Dial-up
(b) Leased-lines
(c) ISDN
(d) Both (a) and (b).
Answer:
(d) Both (a) and (b).

UP Board Solutions for Class 10 Computer Science

Balaji Class 10 Maths Solutions Chapter 11 Height and Distance Ex 11.1 ऊँचाई एवं दूरी

Ex 11.1 Height and Distance बहुविकल्पीय प्रश्न (Multiple Choice Questions)

सही विकल्प का चयन कीजिए।

प्रश्न 1.
जिस समय सूर्य का उन्नयन कोण 45° था तो एक मीनार की परछाई, उस मीनार की लम्बाई से-
(a) बराबर है।
(b) अधिक है।
(c) कम है।
(d) इनमें से कोई नहीं
हल:
∵ मीनार की ऊँचाई = AB, (UPBoardSolutions.com) मीनार की छाया = BC
∆ABC में,

∴ मीनार की ऊँचाई = मीनार की छाया अतः विकल्प (a) सही है।

प्रश्न 2.
किसी स्तम्भ की ऊँचाई उसकी छाया से [latex] \sqrt{{3}} [/latex] गुणा है। सूर्य के उन्नयन कोण का मान होगा-
(a) 45°
(b) 60°
(c) 30°
(d) इनमें से कोई नहीं
हलः
खम्भे की ऊँचाई AB = [latex] \sqrt{{3}} [/latex] × खम्भे की छाया
AB = [latex] \sqrt{{3}} [/latex] × (UPBoardSolutions.com) BC
∆ABC में,

अतः विकल्प (b) सही है।

प्रश्न 3.
एक मीनार के आधार से 20 मीटर दूर भूमि पर स्थित एक बिन्दु से मीनार की चोटी का उन्नयन कोण 30° है। तब मीनार की ऊँचाई-
(a) 20[latex] \sqrt{{3}} [/latex] मीटर
(b) 20 मीटर
(c) [latex]\frac{20}{3 \sqrt{3}}[/latex] मीटर
(d) इनमें से कोई नहीं
हलः

प्रश्न 4.
यदि सूर्य का उन्नयन कोण 45° है। तब h मीटर के स्तम्भ की परछाई होगी-
(a) [latex]\frac{h}{2}[/latex] मीटर
(b) [latex]\frac{h}{3}[/latex] मीटर
(c) h मीटर
(d) इनमें से कोई नहीं
हलः
मीनार की ऊँचाई, (UPBoardSolutions.com) AB = h मी

अतः विकल्प (c) सही है।

प्रश्न 5.
एक पेड़ सतह पर ऊर्ध्वाधर खडा है। पेड से 10[latex] \sqrt{{3}} [/latex] मीटर दूर सतह पर किसी बिन्दु से पेड़ की ऊपरी चोटी का उन्नयन कोण 60° है। तब पेड़ की ऊँचाई होगी-
(a) 30 मीटर
(b) 60 मीटर
(c) 10 मीटर
(d) इनमें से कोई नहीं
हलः
माना पेड की ऊँचाई (UPBoardSolutions.com) = h मीटर
∆ABC में,

प्रश्न 6.
किसी समय एक स्तम्भ की परछाई उसकी लम्बाई के बराबर है तब सूर्य का उन्नयन कोण होगा-
(a) [latex]\frac{\pi}{4}[/latex]
(b) [latex]\frac{\pi}{3}[/latex]
(c) [latex]\frac{\pi}{6}[/latex]
(d) इनमें से कोई नहीं
हलः
माना सूर्य का उन्नयन कोण = θ
∵ दिया है, AB = AC …(1)
∆ABC में,


अतः विकल्प (a) सही है।

Ex 11.1 Height and Distance लघु उत्तरीय प्रश्न (Short Answer Type Questions)

प्रश्न 7.
किसी स्तम्भ की छाया उसकी ऊँचाई से [latex] \sqrt{{3}} [/latex] गुनी है। सूर्य के उन्नयन कोण का मान ज्ञात कीजिए।
हलः
माना खम्भे की ऊँचाई AB = h मीटर
∴ खम्भे की छाया BC = [latex] \sqrt{{3}} [/latex] × h = [latex] \sqrt{{3}} [/latex]h
मीटर माना खम्भे का उन्नयन कोण = θ

प्रश्न 8.
एक बिजली के खम्भे से 10 मीटर दूर स्थित बिन्दु से बल्ब का उन्नयन कोण 60° है। बल्ब की ऊँचाई ज्ञात कीजिए।
हलः
माना खम्भे पर लगे बल्ब की ऊँचाई AB = h
∆ABC में,

प्रश्न 9.
एक 30 मीटर ऊँचे स्तम्भ से जहाज का अवनमन कोण 30° है। जहाज से स्तम्भ की दूरी ज्ञात कीजिए।
हलः
माना स्तम्भ की ऊँचाई = 30 मीटर
स्तम्भ के शीर्ष से जहाज का (UPBoardSolutions.com) अवनमन कोण = उन्नयन कोण = 30°

प्रश्न 10.
एक बिजली का खम्भा 10 मीटर ऊँचा है। खम्भे को सीधा लम्बवत् रखने के लिए एक तार का सिरा, खम्भे की चोटी से बँधा है तथा दूसरा सिरा भूमि पर स्थिर किया गया है। यदि तार खम्भे के आधार बिन्दु से होकर जाने वाले क्षैतिज के साथ 45° का कोण बनाये तो तार की लम्बाई ज्ञात कीजिए। (NCERT)
हलः
खम्भे की ऊँचाई. AB = 10 मी
∠ACB = 45°

Ex 11.1 Height and Distance दीर्घ उत्तरीय प्रश्न (Long Answer Type Questions)

प्रश्न 11.
एक निरीक्षक AC रेखा के सापेक्ष चलता है जहाँ AC ⊥ AB, AC = 200 मीटर, ∠ ACB = 45%, तब नदी के विपरीत कोनों पर स्थित बिन्दु A व B के बीच की दूरी ज्ञात कीजिए।
हलः
∵ AC ⊥ AB, (UPBoardSolutions.com)
∠ACB = 45°

प्रश्न 12.
किसी वृक्ष जिसकी ऊँचाई 15 मीटर है, का ऊपरी भाग जो आँधी से टूटकर पृथ्वी पर जा लगा है, पृथ्वी से 60° का कोण बनाता है। पृथ्वी से कितनी ऊँचाई पर वृक्ष टूटा है?
हल:
पेड की ऊँचाई, BP = 15 मी
∴ BD = 15, यदि पेड बिन्दु (UPBoardSolutions.com) C से टूटकर जमीन पर बिन्दु A पर लग जाता है।
∵ DC = CA = 15 – x
माना BC = x मीटर

∴ इसलिए पेड पृथ्वी से 6.96 मीटर ऊँचाई से टूटेगा।

प्रश्न 13.
एक सीढ़ी एक ऊर्ध्वाधर दीवार पर इस प्रकार रखी जाती है कि यह दीवार की चोटी तक पहुँचती है। सीढ़ी का पाद दीवार से 1.5 मीटर दूर है और सीढ़ी जमीन से 60° के कोण पर झुकी है। दीवार की ऊँचाई ज्ञात कीजिए। (NCERT)
हलः
माना दीवार की (UPBoardSolutions.com) ऊँचाई = h मीटर

∴ दीवार की ऊँचाई = 2.598 मीटर

प्रश्न 14.
एक स्तम्भ से 20 मीटर दूरी पर स्थित बिन्दु का स्तम्भ के शीर्ष बिन्दु से उन्नयन कोण 30° है। स्तम्भ की ऊँचाई ज्ञात कीजिए। (NCERT)
हलः
माना मीनार की ऊँचाई AB = h मीटर, BC = 20 मीटर
∆ABC में,

प्रश्न 15.
एक गुब्बारा 215 मीटर लम्बे तार से बँधा है तथा क्षैतिज से 60° का कोण बनाता है। गुब्बारे की जमीन से ऊँचाई ज्ञात कीजिए यदि यह माने कि डोरी में कोई ढील नहीं है। (NCERT)
हलः
माना जमीन से गुब्बारा h मीटर की ऊंचाई पर उड रहा है।
∴ AB = h मीटर, AC = 215 मीटर
∆ABC में,

प्रश्न 16.
1.5 मीटर लम्बा एक निरीक्षक 30 मीटर ऊँची मीनार से 28 मीटर दूर खड़ा है, उसकी आँख से मीनार के शीर्ष बिन्दु का उन्नयन कोण ज्ञात कीजिए। (NCERT)
हलः
माना प्रेक्षक की आँख D पर 30 मीटर ऊँची एक मीनार का शीर्ष θ कोण बनाती है।
प्रेक्षक से मीनार की दूरी (UPBoardSolutions.com) CB = 28 मीटर

∴ AB = 30 मीटर,
DC = 1.5 मीटर
∴ AM = AB – DC
= 30 – 1.5
= 28.5 मीटर
∆ADM में,
tanθ = [latex]\frac{A M}{D M}=\frac{28.5}{28}[/latex] ≅ 1 (लगभग) (∵ CB = DM)
∴ θ = 45°

प्रश्न 17.
एक पहाड़ की चोटी से टॉवर के पाद का उन्नयन कोण 60° है तथा टॉवर के शीर्ष से पहाड़ की पाद पर उन्नयन कोण 30° है। यदि टॉवर की ऊँचाई 50 मीटर है तो पहाड़ की ऊँचाई ज्ञात कीजिए। (NCERT)
हलः
माना पहाड़ व टॉवर के बीच (UPBoardSolutions.com) की दूरी + x मीटर

प्रश्न 18.
दो खम्भों के बीच की क्षैतिज दूरी 140 मीटर है। पहले खम्भे के शीर्ष से दूसरे खम्भे के शीर्ष पर अवनमन कोण 30° है। यदि दूसरे खम्भे की ऊँचाई 60 मीटर है तो पहले खम्भे की ऊँचाई ज्ञात कीजिए। (NCERT)
हल:
∵ NQ = MT = 140 मीटर
दूसरी मीनार की ऊँचाई
TQ = MN = 60 मीटर

प्रश्न 19.
50 मीटर ऊँचे एक स्तम्भ से एक खम्भे के शीर्ष व पाद पर अवनमन कोण क्रमशः 45° व 60° हैं। यदि खम्भा एवं स्तम्भ एक ही तल पर स्थित हैं। तो खम्भे की ऊँचाई ज्ञात कीजिए।
हल:
माना खम्भे की ऊँचाई (UPBoardSolutions.com) PQ = h मीटर

Balaji Publications Mathematics Class 10 Solutions

UP Board Solutions for Class 10 Computer Science Chapter 7 Introduction to ‘C’

Introduction to ‘C’ Long Answer Type Questions (8 Marks)

Question 1.
Explain the structure of a ‘C’ program with example. (UP 2019)
Answer:
Structure of ‘C’ Program:
Before understanding the structure of a ‘C’ program you must know these important points:

• ‘C’ is a case sensitive language, it means all the keywords must be written in lower case.
• Key-words can’t be used as a variable or function name.
• Every instruction should end with (;) sign.
• Preprocessor directives (required) should (UPBoardSolutions.com) be there in the beginning.
• Function main () is must for a program.

Now to write a program in ‘C’ we need to follow these steps:
Define preprocessor directives (include header files according to prototype functions, standard I/O library functions to be used).

• Open function main ()
• Assign data types and variables.
• Define the body of the function
• End the function main ()

Example

/* harsh.c : first example for students */
# include
void main ()
{
int a = 10, b = 15, c;
printf (“Hellow students \n”);
c = a + b ;
printf (“The sum of % d and % d is % d”, a, b, c);
}

In the above example the first line
/*harsh.c: first example for students */
is a comment and non-executable. Comments in ‘C’ begins with (/*) and ends with (*/).

Second-line
#include
is a preprocessor directive. The preprocessor processes the ‘C’ program before the compiler. Here stdio.h is a header file consists of standard I/O functions. A header file related to the functions used (UPBoardSolutions.com) in program should be included at the beginning.
The line
void main()
indicates “the beginning of the program”. The compilation of the program starts from main () function.
{, the symbol indicates the beginning of the main () function

The line
int a = 10, b = 15, C;
is for declaration of variables and data types.

Lines
printf (“Hellow students \n”);
C = a + b.
printf (“The sum of % d and % d is % d”, a, b, c);
are the body of the program.
and symbol ‘}’ indicates end of main ( ) function.

Question 2.
What is looping? Write about the different statements used to erect loop in ‘C’?
Answer:
Looping
Looping Statements: A computer program is a set of statements, which is normally executed sequentially. But in most of the cases, it is necessary to repeat certain steps to meet a specific condition. This repetitive operation is done through a loop control structure.
A loop is basically the execution of the sequence of statements repeatedly until a particular condition is true or false. In ‘C’ language following looping statements are used:

while Statements:
The while loop repeats a statement or a set of statements until a certain condition is true.
Syntax

while (condition)
{
statements
}

Here, the condition may be any expression having a non-zero value. The loop continues until the condition is true. When the condition fails, the program body attached with loop (statements), will not be executed.

Example: To print the first 20 natural numbers.

#include<stdio.h>
#include<conio.h>
void main ()
{
int a = 1;
while (a < = 20)
{
printf (“%d”, a);
a++;
}
getch ();
}

do-while statement:
Working of this statement is similar to the working of while statement but (UPBoardSolutions.com) in this, at least one time the attached loop (statements) is executed, no matter whether the condition is true or false.
Synax:

do
{
statements
}
while (condition);

Example: To print first 10 odd numbers.

#include<stdio.h> 
#include<conio.h>
void main ()
{
int a = 1;
do
{
printf (“% d”, a);
a+ = 2;
{while (a <=19)};
}

for loop statement:
The for loop is an ideal looping statement when we know how many times the loop will be executed.
Syntax:

for (initialization; condition; counter)
{
statements
}

Here,

• Initialization is generally an assignment which is used to set the loop control variable, e.g., a = 0.
• Condition always tells the limit of the loop or determines when to exit the loop. e.g., a < 10
• Counter defines how the loop control variable will change each time the loop is (UPBoardSolutions.com) repeated. This may be incremented or decremented. e.g., a++, a-

-.

Example: To print your name 10 times.

#include<stdio.h>
#include<conio.h>
void main ()
{
int i;
char name [20];
clrscr ();
printf (“Enter your name”);
gets(name);
for (i = 1; i <= 10; i++)
puts (name);
}
getch ();
}

Introduction to ‘C’ Short Answer Type Questions (4 Marks)

Question 1.
Explain the character set in ‘C’.
Answer:
Character Set in ‘C’. The set of characters that may appear in a legal ‘C’ program is called the character set for ‘C’. These include some graphics as well as non-graphic characters. The ‘C’ character set consists of upper case and lower case alphabets, (UPBoardSolutions.com) special characters, digits and white spaces. The alphabets and digits together are called the alphanumeric characters.
Alphabets
A, B, C, ………, Y, Z.
a, b, c, ………, y, z.
‘C’ is case sensitive language, it means lower and upper case are different.

Digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

Special Characters

• , → Comma
• % → Percent sign
• . → Period
• ? → Question mark
• ; → Semicolon
• & → Ampersand
• : → Colon
• ^ → Caret
• # → Number sign (Hash)
• * → Asterisk
• ‘ → Apostrophe
• – → Minus sign
• ” → Quotation mark
• + → Plus sign
• ! → Exclamation mark
• / → Slash
• | → Vertical bar
• \ → Backslash
• ~ → Tilde
• < → Opening angle bracket
• > → Closing angle bracket
• _ → Underscore
• $ → Dollar sign
• ( → Left parenthesis
• ) → Right parenthesis
• [ → Left bracket
• ] → Right bracket
• { → left brace
• } → Right brace

Question 2.
What is a variable?
Answer:
Variable: A variable is an entity that has a value and is known to the program by a name. A variable definition associates a memory location with the variable name. A variable can have only one value assigned to it at any given time (UPBoardSolutions.com) during the execution of the program. Its value may change during the execution of the program.
Example:
a = 20, 5;
b = 10;
here, a and b are variables.

Variable names are identifiers used to name variables. They are symbolic names given to memory locations. A variable name consists of a sequence of letters and digits, the first character being a letter. The rules that apply to identifiers also apply to variable names.
Examples of valid variable names are:
a → Class
abcl → employee
Stu-data → 12 MAX

Examples of invalid variable names are:
a’s → illegal character (’)
Stu data → blank space not allowed
2Max → first character should be a letter
Classmarks → comma not allowed

Question 3.
WAP to input 10 numbers and print its sum.
Answer:

#include<stdio.h>
#include<conio.h>
void main ()
int N, SUM = 0, i;
clrscr () ;
for (i=1; i <=10; i++)
{
printf (“Enter a number”);
scanf (“% d”, & N);
SUM = SUM + N;
printf (“\n The sum often numbers is % d”, SUM);
getch ();
}

Question 4.
WAP to find the sum of following series:
Answer:
Sum = [latex]\frac { 1 }{ 1 } +\frac { 1 }{ 2 } +\frac { 1 }{ 3 } +……….+\frac { 1 }{ n } [/latex]

#include<stdio.h>
#include<conio.h>
void main ()
{
int n, i;
float sum;
printf (“Enter the number of terms\n”);
scanf (“%. d”, & n);
i = 1;.
do
{
sum = sum + 1 /i;
i = i + 1;
}
while (i <= n);
printf (“% f\ sum);
getch ();
}

Question 5.
WAP to calculate factorial or any given number.
Answer:

#include<stdio.h>
#include<conio.h>
void main( )
{
int n, i;
long int fact = 1;
clrscr ();
printf(“\n Enter any number”);
scanf(“%d”, & n);
for (i=1; i < = n; i + +)
{
fact = fact *i;
}
printf (“The factorial of % d is % 1d”, n, fact);
getch ();
}

Question 6.
WAP to generate the following series:
1
2 2
3 3 3
4 4 4 4
5 5 5 5 5
Answer:

#include<stdio.h>
#include<conio.h>
void main ( )
{
int i, j;
clrscr ();
for (i=1; i <= 5; i + +)
{
for (j=1; j <= i; j++)
{
printf (“% d\t”, i);
}
printf (“\n”);
}
getch ();

Introduction to ‘C’ Very Short Answer Type Questions (2 Marks)

Question 1.
From where the compilation of the program starts?
Answer:
from main () function.

Question 2.
% operator returns what?
Answer:
Remainder.

Question 3.
Who developed ‘C’ language?
Answer:
Dennis Ritchie and Ken Thompson.

Question 4.
A loop within a loop is known as ……….
Answer:
Nested loop.

Question 5.
Which data type consists of fractional values?
Answer:
float.

Introduction to ‘C’ Objective Type Questions (1 Marks)

There are four alternative answers for each part of the questions. Select the correct one and write it in your answer-book.

Question 1.
A variable name must start with:
(a) A number
(b) An alphabet
(c) $ symbol
(d) # sign.
Answer:
(b) An alphabet

Question 2.
% s is used for:
(a) Character data type
(b) Numeric data type
(c) String data type
(d) Float data type.
Answer:
(c) String data type

Question 3.
‘!=’ is a/an:
(a) Arithmetical operator
(b) Relational operator
(c) Logical operator
(d) Assigning operator.
Answer:
(b) Relational operator

Question 4.
Which header file is used for scanf () and printf ()?
(a) conio.h
(b) stdio.h
(c) math.h
(d) Both (a) and (b).
Answer:
(d) Both (a) and (b).

Question 5.
Which of them is not a looping statement?
(a) for
(b) while
(c) if
(d) do-while.
Answer:
(c) if

UP Board Solutions for Class 10 Computer Science