MCQ on Electronics and Communication

21-Which of the following is a bidirectional device?

(A) Zener diode



(D) Triac


22-The function of NOT gate is to

(A) Invert an input signal

(B) Add two input signals

(C) Multiply two input signals

(D) Perform as a universal gate


23-Which of the following is the fastest switching device?




(D) pentode


24-Henry is the unit of

(A) Capacitance

(B) Power

(C) Inductance

(D) Resistance


25-A dynamic microphone is a ___ type transducer.

(A) Acoustical

(B) Thermal

(C) Optical

(D) Variable resistance


26-The ripple factor of a halfwave rectifier is

(A) 0.482

(B) 0.812

(C) 1.21

(D) 40.6


27-Which of the following is a single input flip-flop?

(A) R-S

(B) D

(C) JK

(D) Clocked RS


28-Antimony is a ___ type of doping material.

(A) trivalent

(B) semiconductor

(C) acceptor

(D) pentavalent


29-IC 7912 is

(A) two input Quad XNOR gate

(B) two input Quad XOR gate

(C) Negative voltage regulator for 12 V

(D) Positive voltage regulator for 12 V


30-Which of the following is an insulator?

(A) Ferrite

(B) Germanium

(C) Silicon

(D) Zinc



21-(D), 22-(A), 23-(A), 24-(C), 25-(A), 26-(C), 27-(B), 28-(D), 29-(C), 30-(A)