# Latches MCQ’s

This set of Digital Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Latches”.

1. Latch is a device with ___________
a) One stable state
b) Two stable state
c) Three stable state
d) Infinite stable states

2. Why latches are called memory devices?
a) It has capability to stare 8 bits of data
b) It has internal memory of 4 bit
c) It can store one bit of data
d) It can store infinite amount of data

3. A latch is an example of a ___________
a) Monostable multivibrator
b) Astable multivibrator
c) Bistable multivibrator
d) 555 timer

4. Two stable states of latches are ___________
a) Astable & Monostable
b) Low input & high output
c) High output & low output
d) Low output & high input

5. The full form of SR is ___________
a) System rated
b) Set reset
d) Set Rated

6. The outputs of SR latch are ___________
a) x and y
b) a and b
c) s and r
d) q and q’

7. How many types of latches are ___________
a) 4
b) 3
c) 2
d) 5

8. The SR latch consists of ___________
a) 1 input
b) 2 inputs
c) 3 inputs
d) 4 inputs

9. The NAND latch works when both inputs are ___________
a) 1
b) 0
c) Inverted
d) Don’t cares

10. The inputs of SR latch are ___________
a) x and y
b) a and b
c) s and r
d) j and k

11. When both inputs of SR latches are low, the latch ___________
a) Q output goes high
b) Q’ output goes high
c) It remains in its previously set or reset state
d) it goes to its next set or reset state

12. The first step of the analysis procedure of SR latch is to ___________
a) label inputs
b) label outputs
c) label states
d) label tables

13. When a high is applied to the Set line of an SR latch, then ___________
a) Q output goes high
b) Q’ output goes high
c) Q output goes low
d) Both Q and Q’ go high

14. When both inputs of SR latches are high, the latch goes ___________
a) Unstable
b) Stable
c) Metastable
d) Bistable