Digital Logic and Design MCQs with Answers
Practice important Digital Logic and Design MCQs with answers and explanations.
Multiple Choice Questions
Q411: A 3-to-8 decoder has how many possible output lines?
- A: 3
- B: 4
- C: 8
- D: 16
View Answer
C
Q412: A frequency divider circuit is used to ________.
- A: Increase the frequency
- B: Decrease the frequency
- C: Maintain the frequency
- D: Randomize the frequency
View Answer
B
Q413: In the 16-bit ALU with Look-Ahead Carry Generator, how is Carry In for ALU1 determined?
- A: Directly from input A
- B: From the Look-Ahead Carry Generator
- C: From the previous ALU's Carry Out
- D: Directly from input B
View Answer
B
Q414: What does the output C1 from the Look-Ahead Carry Generator represent?
- A: Carry Out of ALU0
- B: Carry In to ALU1
- C: Group Carry for ALU0
- D: Group Carry for ALU1
View Answer
B
Q415: What is the primary role of a 4-bit Comparator?
- A: To compare two 4-bit numbers and determine equality
- B: To perform arithmetic operations on 4-bit numbers
- C: To generate carry bits
- D: To count the number of 1s in a 4-bit number
View Answer
A
Q416: In a cascaded 4-bit Comparator, what happens if the most significant bits are equal?
- A: The least significant bits are compared
- B: The least significant bits are ignored
- C: The comparison is reset
- D: The system generates an error
View Answer
A
Q417: What is the main use of the 74HC85 MSI chip?
- A: For 2-bit comparisons only
- B: To decode 2-to-4 binary codes
- C: For cascading multiple 4-bit Comparators
- D: To perform 16-bit arithmetic operations
View Answer
C
Q418: What type of outputs does the 74LS139 MSI chip have?
- A: Active-high outputs
- B: Active-low outputs
- C: Both active-high and active-low outputs
- D: None of the above
View Answer
B
Q419: What happens to the outputs of a 2-to-4 Decoder when the input is 00?
- A: O0 is activated, others are deactivated
- B: O1 is activated, others are deactivated
- C: O2 is activated, others are deactivated
- D: O3 is activated, others are deactivated
View Answer
A
Q420: How are the cascading inputs of a 2-bit Iterative Circuit based Comparator connected?
- A: To fixed logic inputs
- B: To cascading outputs of the next module
- C: To ground and Vcc
- D: Directly to each other
View Answer
A