Top 350+ Solved Digital Electronics and Logic Design MCQ Questions Answer
Q. Which of the logic families listed below allows the highest operating frequency?
a. 74as
b. ecl
c. hcmos
d. 54s
Q. What does ECL stand for?
a. electron- coupled logic;
b. emitter- coupled logic;
c. energy- coupled logic;
d. none of above
Q. What is unique about TTL devices such as the 74S00?
a. the gate transistors are silicon (s), and the gates therefore have lower values of leakage current.
b. the s denotes the fact that a single gate is present in the ic rather than the usual package of 2–6 gates.
c. the s denotes a slow version of the device, which is a consequence of its higherpower rating.
d. the devices use schottky transistors anddiodes to prevent them from going into saturation; this results in faster turn on and turn off times, which translates intohigher frequency operation.
Q. he bipolar TTL logic family that was developed to increase switching speed by preventing transistor saturation is:
a. emitter- coupled logic (ecl).
b. current- mode logic (cml).
c. transistor- transistor logic (ttl).
d. emitter- coupled logic (ecl) and transistor- transistor logic (ttl).
Q. In TTL the noise margin is between
a. 0.4 v and 0.8 v.
b. 0.0 v and 0.4 v.
c. 0.0 v and 0.5 v.
d. 0.0v and0.8 v.
Q. What is the transitive voltage for the voltage input of a CMOS operating from 10V supply
a. 1v
b. 5v
c. 10v
d. 15v
Q. What is the transitive voltage for the voltage input of a CMOS operating from 10V supply ?
a. 1v
b. 5v
c. 10v
d. 20v
Q. Which of the following logic families is well suited for high-speed operations ?
a. ttl
b. ecl
c. mos
d. cmos
Q. he digital logic family which has the lowest propagation delay time is
a. ecl
b. ttl
c. cmos
d. pmos
Q. Which of the following statements is wrong ?
a. propagation delay is the time required for a gate to change its state
b. noise immunity is the amount of noise which can be applied to the input of a gate without causing the gate to change state
c. fan-in of a gate is always equal to fan-out of the same gate
d. operating speed is the maximum frequency at which digital data can be applied to a gate
Q. Which table shows the logical state of a digital circuit output for every possible combination of logical states in the inputs ?
a. function table
b. truth table
c. routing table
d. asciitable