Which logic gate produces a low output only when all inputs are high?
A NAND
B NOR
C XOR
D XNOR
A NAND gate produces a low (0) output only when all inputs are high (1). In all other cases, the output is high (1).
What is the decimal equivalent of the binary number 101010101010?
A 9
B 10
C 11
D 12
Binary 101010101010 equals (1×2³)+(0×2²)+(1×2¹)+(0×2⁰)=10.
What is the primary purpose of a latch in digital circuits?
A Amplify signals
B Perform arithmetic operations
C Store one bit of data
D Decode binary inputs
A latch is a bistable device that stores one bit of data and can maintain its state indefinitely until triggered to change.
Which combinational circuit converts binary data into a single active output?
A Decoder
B Encoder
C Multiplexer
D Counter
An encoder takes multiple binary inputs and converts them into a single active output based on a priority scheme.
Which Boolean algebra law is represented by A+AB=A?
A Absorption Law
B Distributive Law
C Identity Law
D Idempotent Law
The Absorption Law states that A+AB=A, as AB is already included in A.
What is the function of a ring counter?
A Store data temporarily
B Perform multiplication
C Cycle through a predefined sequence of states
D Amplify clock signals
A ring counter is a sequential circuit where only one flip-flop is set at a time, and the logic circulates through the sequence.
What is the binary representation of the decimal number 8?
A 111
B 1010
C 1000
D 1100
The binary equivalent of decimal 8 is 1000, calculated as 2³.
What is the difference between a latch and a flip-flop?
A Latches operate with a clock signal, flip-flops do not
B Flip-flops operate with a clock signal, latches do not
C Both operate with a clock signal
D Neither use a clock signal
Latches are level-triggered, while flip-flops are edge-triggered and require a clock signal for operation.
What is the purpose of a parity bit in digital communication?
A Perform logical operations
B Detect errors in data transmission
C Convert data formats
D Amplify signals
A parity bit is added to a binary message to ensure that the total number of 1s (or 0s) is even or odd, helping detect transmission errors.
How many input combinations are possible for a 3-input logic gate?
A 4
B 6
C 8
D 10
For a logic gate with n inputs, the number of possible combinations is 2ⁿ. For n=3, 2³=8.
What is a combinational circuit with 2ⁿ outputs and n inputs called?
A Decoder
B Multiplexer
C Counter
D Encoder
A decoder has 2ⁿ outputs and n inputs. It activates one output based on the input binary code.
What is the purpose of a synchronous counter?
A Reduce propagation delay
B Amplify clock signals
C Store multiple bits of data
D Perform logical operations
A synchronous counter updates all its flip-flops simultaneously using a common clock signal, reducing propagation delays.
Which of the following circuits is used to implement multiplexing?
A XOR Gate
B AND Gate
C OR Gate
D Selector Circuit
A multiplexer uses a selector circuit to choose one input from several and direct it to the output.
What is the main purpose of a digital comparator?
A Compare two binary numbers
B Store binary data
C Perform arithmetic operations
D Shift data
A digital comparator compares two binary inputs and provides outputs indicating equality, greater than, or less than.
Which type of flip-flop toggles its state with every clock pulse?
A JK Flip-Flop
B D Flip-Flop
C SR Flip-Flop
D T Flip-Flop
A T flip-flop changes (toggles) its state on every clock pulse if the input T is high.
What is the function of a clock divider circuit?
A Store data
B Reduce the clock frequency
C Perform logical operations
D Amplify clock signals
A clock divider reduces the frequency of a clock signal by dividing it by a predefined factor.
What is the hexadecimal equivalent of binary 101011001010110010101100?
A AC
B BC
C AB
D A8
Group binary digits into 4-bit segments: 1010=A, 1100=C. The hexadecimal equivalent is AC.
Which memory type is used for high-speed access in processors?
A RAM
B ROM
C Cache Memory
D Flash Memory
Cache memory provides high-speed access to frequently used data, improving processor performance.
What is the main difference between ROM and RAM?
A ROM is faster than RAM
B RAM is non-volatile, ROM is volatile
C ROM is non-volatile, RAM is volatile
D Both are non-volatile
ROM retains data without power (non-volatile), while RAM requires power to maintain data (volatile).
What does the term “propagation delay” refer to in digital circuits?
A The time taken to amplify a signal
B The time for a signal to travel through a logic gate
C The time for a counter to reset
D The time for memory access
Propagation delay is the time interval between a change in the input of a logic gate and the corresponding change in its output.