BEE BEE Bachelor of Electrical Engineering Digital Logic and Systems Questions and Answers 2 — Questions and Answers
Question 1: What is the output of an XOR gate when both inputs are 1?
- 0 (Correct answer)
- 1
- Undefined
- High impedance
Correct answer: 0
An XOR gate outputs 0 when both inputs are the same value.
Question 2: Which flip-flop is used to divide the input clock frequency by 2?
- T flip-flop with T=1 (Correct answer)
- D flip-flop with D=0
- SR flip-flop with S=1
- JK flip-flop with J=0, K=0
Correct answer: T flip-flop with T=1
A T flip-flop with T tied to 1 toggles on every clock edge, producing an output at half the clock frequency.
Question 3: How many select lines are needed for an 8-to-1 multiplexer?
- 3 (Correct answer)
- 2
- 4
- 8
Correct answer: 3
An 8-to-1 multiplexer requires 3 select lines because 2^3 = 8 input combinations.
Question 4: What does a Karnaugh map primarily help minimize?
- Boolean expressions (Correct answer)
- Clock frequency
- Power consumption
- Memory usage
Correct answer: Boolean expressions
A Karnaugh map is a graphical method used to simplify Boolean algebra expressions and reduce the number of logic gates needed.
Question 5: In a 4-bit synchronous counter, what is the maximum count value in decimal?
- 15 (Correct answer)
- 16
- 8
- 10
Correct answer: 15
A 4-bit counter counts from 0 to 2^4 - 1 = 15, giving a maximum decimal value of 15.
Question 6: Which logic family offers the lowest power consumption in static conditions?
- CMOS (Correct answer)
- TTL
- ECL
- BiCMOS
Correct answer: CMOS
CMOS logic draws negligible static power because its complementary transistor pairs ensure one is always off in steady state.
BEE BEE Bachelor of Electrical Engineering Digital Logic and Systems Questions and Answers 2
What is the output of an XOR gate when both inputs are 1?