VII

 

STD: VII – Computer (Question Bank with Answers)

I. Choose the Correct Answer

1. How many unique digits are used in the octal number system?
a) 8  b) 16  c) 64  d) 56
Answer: a) 8

2. A simple ON/OFF switch can be used to represent a single:
a) Byte  b) Bit  c) Hexadecimal  d) Decimal number
Answer: b) Bit

3. In the hexadecimal number system, which letter represents the decimal value 15?
a) A  b) B  c) E  d) F
Answer: d) F

4. The program stored in ROM that helps the computer start up is called:
a) HTTP  b) BIOS  c) USB  d) RAM
Answer: b) BIOS

5. Which of the following statements about the modem is TRUE?
a) It stores audio permanently
b) It helps connect a computer to the internet
c) It helps convert video files
d) It is used to increase memory
Answer: b) It helps connect a computer to the internet

6. The process that translates analog signals into digital signals is called:
a) Demodulation  b) Static conversion  c) Modulation  d) Dynamic conversion
Answer: a) Demodulation

7. Which number system uses only the digits 0 and 1?
a) Decimal  b) Binary  c) Octal  d) Hexadecimal
Answer: b) Binary

8. Which of the following is an input device?
a) Monitor  b) Printer  c) Keyboard  d) Speaker
Answer: c) Keyboard

9. Which hardware component performs arithmetic and logical operations?
a) RAM  b) CPU  c) ROM  d) Hard Disk
Answer: b) CPU

10. Which hexadecimal digit represents the decimal value 12?
a) A  b) B  c) C  d) D
Answer: c) C

11. Which of the following is an output device?
a) Mouse  b) Scanner  c) Monitor  d) Microphone
Answer: c) Monitor

---

II. Fill in the Blanks

Words: (Binary, Motherboard, CPU, SMPS, Borrow, 0, ROM, Modem, Pixel, 16)

1. Computers understand and process information using only __________ digits.
   Answer: Binary

2. The main circuit board of the computer is called the __________.
   Answer: Motherboard

3. The __________ is often referred to as the brain of the computer.
   Answer: CPU

4. The __________ provides different voltage levels to various internal components.
   Answer: SMPS

5. In binary subtraction, when you subtract 1 from 0, you must __________ from the next higher position.
   Answer: Borrow

6. In binary multiplication, 1 × 0 equals __________.
   Answer: 0

7. The __________ number system has a base of 2.
   Answer: Binary

8. __________ is non-volatile memory.
   Answer: ROM

9. A __________ is used to connect a computer to the Internet.
   Answer: Modem

10. A digital image is made up of tiny dots called __________.
    Answer: Pixel

11. The hexadecimal number system has a base of __________.
    Answer: 16

---

III. Name the Following

1. The concept where the value of a digit depends on its position in the number.
   Answer: Positional Value System (Place Value)

2. The smallest addressable unit of a digital image represented by binary color data.
   Answer: Pixel

3. The letter in hexadecimal that represents the decimal value 10.
   Answer: A

4. The type of arithmetic computers perform using only 0s and 1s.
   Answer: Binary Arithmetic

5. The smallest unit of information in a computer.
   Answer: Bit

6. The device that converts digital signals into analog signals and vice versa.
   Answer: Modem

7. The memory that stores the BIOS program.
   Answer: ROM

8. The number system with base 16.
   Answer: Hexadecimal Number System

9. The part of the computer that supplies electrical power to all components.
   Answer: SMPS (Switched Mode Power Supply)

---

IV. Answer the Following

1. Why is SMPS important?
Answer: SMPS supplies the correct and stable voltage to all internal components of the computer and protects them from power fluctuations.

2. What are peripheral devices?
Answer: Peripheral devices are external hardware devices connected to a computer to provide input, output, or storage functions, such as a keyboard, mouse, printer, and scanner.

3. What is the difference between a sound card and a video card?

Sound Card	Video Card
Processes audio signals.	Processes graphics and video signals.
Produces sound through speakers.	Displays images and videos on the monitor.

4. Write the rules to convert an octal number to a decimal number. Explain with an example.
Answer:

• Write the place values as powers of 8 from right to left.

• Multiply each digit by its place value.

• Add all the products.

Example:
345₈ = (3 × 8²) + (4 × 8¹) + (5 × 8⁰)
= (3 × 64) + (4 × 8) + (5 × 1)
= 192 + 32 + 5 = 229₁₀

5. Multiply 111₂ and 001₂.
Answer:

   111
×  001
------
   111

Result = 111₂

6. What is the difference between RAM and ROM?
Answer: RAM is temporary (volatile) memory used while the computer is running, whereas ROM is permanent (non-volatile) memory that stores startup instructions.

7. Explain the working of a modem.
Answer: A modem converts digital signals from a computer into analog signals for transmission and converts incoming analog signals back into digital signals.

8. Convert the octal number 257₈ to its decimal equivalent.
Answer:
257₈ = (2 × 8²) + (5 × 8¹) + (7 × 8⁰)
= 128 + 40 + 7
= 175₁₀

9. Differentiate between binary and hexadecimal number systems.

Binary	Hexadecimal
Base 2	Base 16
Uses digits 0 and 1	Uses digits 0–9 and A–F

10. Perform the following binary subtraction: 1011₂ − 0101₂.

  1011
- 0101
------
  0110

Answer: 0110₂