MODEL QUESTION SOLUTION

 COMPUTER SCIENCE

ACCORDING TO CDC 2077

MODEL QUESTION SOLUTION

CLASS: 11                                                                                           FULL MARK: 50

TIME: 2 HOURS

 

Group A: Multiple Choice Questions Tick the best alternative.   (9 x 1=9)

1. Which one of the following is an input device?

      a) speaker          b) printer                          c) monitor          d) mouse

 

2. Which of the following is NOT a bus type?

      a) Address bus    b) Data bus       c) Memory bus  d) Control bus

                         

3. How to represent Boolean F(x,y)=x.y in logic gate?

 

 

 

Ans: a)

 

4. Which scheduling algorithm allocates the CPU first to the process that requests the CPU first?

     a) first-come, first-served scheduling             c) shortest job scheduling  

     b) priority scheduling                                             d) Round robin scheduling

 

5. Which operator is used to start for enter the formula in Excel cell?     

     a) $                                 b) @                              c) =                                       d) +

 

6. Which looping process checks the test condition at the end of the loop?    

     a) for                            b) while                        d) do-whiled         e) Nested loop

 

7. How to insert an image in web page using HTML tag?
    a) <img=...>                b) <img source..>       c) <img src=...>   d) <img href=..>

 

8. Which image format is best used for photographs and offers a small file size?(U)

     a) PNG                           b) GIF                         c) BMP                           d) JPEG

 

9. Which of following is monitors user activity on internet and transmit that information in the background to someone else? (U)

    a) Malware                  b) Spyware                c) Adware                   d) Virus

 

                                                 Group 'B'
Give short answer to the following questions.             (5 x 5=25)

1. Explain different types of secondary memory of computer system.

 Ans:

     Secondary memory is also known as external memory or non-volatile. It is slower than main memory. These are used for storing data/Information permanently. CPU directly does not access these memories instead they are accessed via input-output routines. Contents of secondary memories are first transferred to main memory, and then CPU can access it. The types of secondary memory are below:

1.     Magnetic Disk

2.     Floppy Disk

3.     Hard Disk

4.     Optical Disks

Magnetic Disk: The Magnetic Disk is Flat, circular platter with metallic coating that is rotated beneath read/write heads. It is a Random access device; read/write head can be moved to any location on the platter.

Floppy Dis: These are small removable disks that are plastic coated with magnetic recording material. Floppy disks are typically 3.5″ in size (diameter) and can hold 1.44 MB of data. This portable storage device is a rewritable media and can be reused a number of times. Floppy disks are commonly used to move files between different computers.

Hard Disk: Another form of auxiliary storage is a hard disk. A hard disk consists of one or more rigid metal plates coated with a metal oxide material that allows data to be magnetically recorded on the surface of the platters.

                                                     OR

    Describe the decimal to binary number conversion process with example.

Ans:

      A decimal number has base 10 and a binary number has base 2. In decimal to binary conversion, the base of the number also changes, i.e. from base 10 to base 2. All the decimal numbers have its equivalent binary numbers. These binary numbers are majorly used in computer applications, where it is used for programming or coding purpose. This is because computers understand the language of binary digits, o and 1.

Hence, once we give the input to the computer system in the decimal form, it converts them into binary digits, performs the required operations and provides the output with into decimal form again. Now, learn here how the decimal number can be represented here in binary form. But before learning the steps for conversion, first, let us see the table to know the equivalent binary number for a decimal number.

 

2. What are the functions of operating system? Describe.

   Ans:

         The functions of operating system are below:

a.     I/O management :

b.     Command interpreter;

c.      Data management;

d.     Memory Management;

e.     Process management;

f.       Devices management;

g.     File management;

h.     Time sharing;

Some of them are mention below

1.     Processor Management — The OS (Operating System) ensures that each process/application receives enough time from the processor to function properly. It also tries to utilize as many processor cycles as possible for the real time work.

2.     Memory Storage and Management — The OS (Operating System) manages the sharing of internal memory among the multiple applications. It also ensures that one process should not consume the memory allocated to another process. An OS has to make efficient utilisation of different types of memory (RAM, Cache, etc.) within the system, so as to ensure proper execution of every process.

3. Define different types of CSS.

Ans:

     Cascading Style Sheet (CSS) is used to set the style in web pages that contain HTML elements. It sets the background color, font-size, font-family, color,… etc property of elements on a web page. There are three types of CSS which are given below: 

 

·         Inline CSS

·         Internal or Embedded CSS

·         External CSS

 

Inline CSS: Inline CSS contains the CSS property in the body section attached with element is known as inline CSS. This kind of style is specified within an HTML tag using the style attribute. 

 

Internal or Embedded CSS: This can be used when a single HTML document must be styled uniquely. The CSS rule set should be within the HTML file in the head section i.e the CSS is embedded within the HTML file. 

 

External CSS: External CSS contains separate CSS file which contains only style property with the help of tag attributes (For example class, id, heading, … etc). CSS property written in a separate file with .css extension and should be linked to the HTML document using link tag. This means that for each element, style can be set only once and that will be applied across web pages.

                                                      OR

    Explain the different components of multimedia.

Ans:

      The various components of multimedia are Text, Audio, Graphics, Video and Animation. All these components work together to represent information in an effective and easy manner.

1)Text: Text is the most common medium of representing the information. In multimedia, text is mostly use for titles, headlines, menu etc. The most commonly used software for viewing text files are Microsoft Word, Notepad, Word pad etc. Mostly the text files are formatted with, DOC, TXT etc extension.

2)Audio: In multimedia audio means related with recording, playing etc. Audio is an important component of multimedia because this component increase the understandability and improves the clarity of the concept. audio includes speech, music etc. The commonly used software for playing audio files are:

i) Quick Time

ii) Real player
iii) Windows Media Player

3)Graphics: Every multimedia presentation is based on graphics. The used of graphics in multimedia makes the concept more effective and presentable.the commonly used software for viewing graphics are windows Picture, Internet Explorer etc. The commonly used graphics editing software is Adobe Photoshop through which graphics can be edited easily and can be make effective and attractive.

4)Video: Video means moving pictures with sound. It is the best way to communicate with each other. In multimedia it is used to makes the information more presentable and it saves a large amount of time. The commonly used software for viewing videos are:

i) Quick Time

ii) Window Media Player
iii) Real Player

5)Animation: In computer animation is used to make changes to the images so that the sequence of the images appears to be moving pictures. An animated sequence shows a number of frames per second to produce an effect of motion in the user's eye. Some of the commonly used software for viewing animation are:

i) Internet Explorer

ii) Windows Pictures
iii) Fax Viewer

These are the components of Multimedia. Now I am going to talk about its applications.

4. Differentiate between the do and while loop.

   Ans:

         The differentiate between do and while loop are below in table:

	Do-while loop	While loop
1.	In do while loop test condition is evaluated after the loop is executed.	In the while loop the test condition is evaluated before the loop is executed.
2.	It is an exit controlled loop	It is an entry controlled loop
3.	It has two keywords do and while.	It has a keyword while
4.	Loop is terminated with semicolon.	Loop is not terminated with semicolon.

 

5. Suggest the prevention methods of cybercrime.

 Ans:

           The prevention methods of cybercrime are mention in point

1.     Use full services internet security suite

2.     Use strong passwords

3.     Keep your software update.

4.     Manage your social media setting.

5.     Do not download unnecessary software, apk, video, game etc..

6.     Backup data and information regularly to reduce the damage.

7.     Active 2FA on every online account when possible.

8.     Use two-factor authentication (2FA) apps or physical security keys.

9.     Use antivirus software to prevent of hacking, virus etc..

10.                        Be careful while using public WiFi.

   

                                                    Group 'C'

Give long answer to the following question           (2 x 8=16)

6. Explain computer architecture with block diagram and functions of its components.

   Ans:

         The design, arrangement, construction or organization of the different part of the computer is known as architecture. Computer Block Diagram System: Mainly computer system consists of three parts that are central processing unit (CPU), Input Devices, and Output Devices. The Central Processing Unit (CPU) is divided into two parts again: arithmetic logic unit (ALU) and the control unit (CU). The set of instruction is in the form of raw data.

A large amount of data is stored in the computer memory with the help of primary and secondary storage devices. The CPU is like the heart/brain of the computer. The user does not get the desired output, without the necessary option taken by the CPU.  The Central processing unit (CPU) is responsible for the processing of all the instructions which are given by the user to the computer system.

                             

The data is entered through input devices such as the keyboard, mouse, etc. This set of instruction is processed by the CPU after getting the input by the user, and then the computer system produces the output. The computer can show the output with the help of output devices to the user, such as  monitor, printer, etc.

·         CPU (Central Processing Unit)

·         Storage Unit

·         ALU(Arithmetic Logic Unit)

·         Control Unit

 

                                                            OR

   Write a program to input the elements of 4 x 3 matrix and prints its elements properly using array.

 

7. Draw AND, OR, XOR and XNOR gates with truth table and logic gates.

  Ans:

AND:

OR:

XOR:

XNOR: