2024 PYQs
1. Which of the following is the most commonly used alphanumeric code for representing characters from different languages in a computer system?
A. EBCDIC
B. Unicode
C. Excess-3 Code
D. Gray Code
Answer: B. Unicode
2. What is the binary equivalent of hexadecimal number F4?
A. 11111001
B. 11110100
C. 11111100
D. 11111010
Answer: B. 11110100
3. Which of the following 4-bit numbers is equal to its own 2's complement?
A. 1010
B. 0101
C. 1000
D. More than one of the above
Answer: C. 1000
4. How many bits are used to represent a single decimal digit in Gray Code?
A. 4 bits
B. 8 bits
C. 16 bits
D. 10 bits
Answer: A. 4 bits
5. What is the Gray Code equivalent of binary number 0100?
A. 0011
B. 1100
C. 0110
D. 1001
Answer: C. 0110
6. Gray Code is commonly used in which application?
A. Digital communication
B. Data encryption
C. Analog-to-digital conversion
D. Error detection
Answer: C. Analog-to-digital conversion
7. What is the Gray Code equivalent of binary number 1101?
A. 1110
B. 1011
C. 1010
D. 1001
Answer: B. 1011
8. When converting a binary number to Gray Code, what is obtained by XORing the MSB of the binary number with the next bit?
A. MSB of Gray Code
B. LSB of Gray Code
C. XOR of all binary bits
D. XOR of all Gray Code bits
Answer: B.
9. What is the first step in binary multiplication using the simple method after aligning the digits?
A. Multiply LSB by multiplier
B. Multiply MSB by multiplier
C. Multiply LSB by multiplicand
D. Add the digits
Answer: B. Multiply the MSB by the multiplier
10. Altair 8800, one of the earliest successful microcomputers, was introduced in which year?
A. 1965
B. 1975
C. 1985
D. 1995
Answer: B. 1975
11. What is an important advantage of EEPROM over EPROM?
A. EEPROM is always faster
B. EEPROM does not require UV light for erasing
C. EEPROM has greater capacity
D. EEPROM is volatile
Answer: B. EEPROM does not require UV light for erasing
12. What is the minimum value of m + n for a decoder having m input lines and n output lines used to uniquely address a byte-addressable 1 KB RAM?
A. 18
B. 1034
C. 10
D. 1024
Answer: B. 1034
Concept:
1 KB = 1024 bytes = 2¹⁰ addresses.
Therefore, 10 input/address lines and 2¹⁰ = 1024 output lines are required.
13. A multiplexer with a 4-bit data-select input is:
A. 4:1 MUX
B. 2:1 MUX
C. 16:1 MUX
D. 8:1 MUX
Answer: C. 16:1 Multiplexer
14. In a Johnson counter, the number of possible states represented by n flip-flops is:
A. n
B. 2n
C. 2ⁿ
D. 2ⁿ⁻¹
Answer: B. 2n
15. Which flip-flop enters an invalid/forbidden state when both inputs are set to 1?
A. S-R flip-flop
B. J-K flip-flop
C. D flip-flop
D. T flip-flop
Answer: A. S-R flip-flop
16. An S-R flip-flop can be used to construct a D flip-flop by connecting:
A. S = D, R = D
B. S = D, R = D′
C. S = Q, R = Q′
D. S = Q′, R = Q
Answer: B. S = D, R = D′
2023 PYQs
17. The hexadecimal number F4 is equivalent to which binary number?
A. 11111001
B. 11110100
C. 11111100
D. 11111010
Answer: B. 11110100
18. Which of the following is a self-complementing binary code in which adjacent codes differ in only one bit position?
A. BCD
B. ASCII
C. Gray Code
D. EBCDIC
Answer: C. Gray Code
19. In a microcomputer system, how is the width of the data bus generally measured?
A. Kilobytes
B. Megahertz
C. Bits
D. Address lines
Answer: C. Bits
20. Which application is a common use of a microcontroller?
A. Operating systems for computers
B. Entertainment systems in airplanes
C. Engine control in cars
D. Weather forecasting systems
Answer: C. Engine control in cars
21. What is the main purpose of the clock/oscillator circuit in an ideal microcomputer?
A. Satellite communication
B. Air traffic control
C. Generate timing signals to synchronize operations
D. Cooling components
Answer: C. Generate timing signals
22. What does Harvard architecture refer to in the context of microcontrollers?
A. Separate memory spaces for instructions and data
B. A microcontroller with advanced addressing modes
C. A microcontroller with a large number of I/O ports
D. A microcontroller with multiple CPUs
Answer: A. Separate memory spaces for instructions and data
2020 PYQs
23. Which component was used in first-generation computers?
A. Vacuum tubes
B. Registers
C. Transistors
D. Magnetic cores
Answer: A. Vacuum tubes
24. Boolean algebra can be used for:
A. Designing digital computers
B. Building logic symbols
C. Circuit theory
D. Building algebraic functions
Answer: A. Designing digital computers
25. Which of the following represents the canonical forms of a Boolean expression?
A. OR and XOR
B. NOR and XNOR
C. MAX and MIN
D. SOM and POM
Answer: D. SOM and POM
2019 PYQs
26. Which logical operation is represented by the + sign in Boolean algebra?
A. OR
B. NOT
C. NOR
D. AND
Answer: A. OR
27. Consider:
A = 110001
B = 001100
What is the result of:
(A AND B) OR (NOT A AND NOT B)?
A. 000000
B. 110001
C. 001100
D. 000010
Answer: D. 000010
