# Digital Electronics MCQs

## In a JK master slave flip flop

• A. master is clocked when clock is low
• B. slave is clocked when clock is high
• C. master is clocked when clock is high and slave is clocked when clock is low
• D. master is clocked when clock is low and slave is clocked when clock is high

## Which of the following is susceptible to race condition?

• A. R-S latch
• B. D latch
• C. Both R - S and D latches
• D. None of the above

## In a positive edge triggered JK flip flop

• A. High J and High K produce inactive state
• B. Low J and High K produce inactive state
• C. Low J and Low K produce inactive state
• D. High J and Low K produce inactive state

## In a positive edge triggered D flip flop

• A. D input is called direct set
• B. Preset is called direct reset
• C. Present and clear are called direct set and reset respectively
• D. D input overrides other inputs

## A 3 input NAND gate is to be used as inverter. Which of the following will give better results?

• A. The two unused inputs are left open
• B. The two unused inputs are connected to 0
• C. The two unused inputs are connected to 1
• D. None of the above

## Assertion (A): A multiplexer can be used for data routing. Reason (R): A multiplexer has one input and many outputs.

• A. Both A and R are correct and R is correct explanation of A
• B. Both A and R are correct but R is not correct explanation of A
• C. A is true, R is false
• D. A is false, R is true

• A. 8
• B. 12
• C. 24
• D. 32

## DeMorgan’s first theorem shows the equivalence of

• A. OR gate and Exclusive OR gate
• B. NOR gate and Bubbled AND gate
• C. NOR gate and NAND gate
• D. NAND gate and NOT gate

## Using the same flip flops

• A. a synchronous flip flop can operate at higher frequency than ripple counter
• B. a ripple counter can operate at higher frequency than synchronous counter
• C. both ripple and synchronous counter can operate at the same frequency
• D. can not determine