Multiple Choice Questions (MCQ) on Basic Electrical Engineering

21-BY 127 is a:

(A) PNP transistor

(B) NPN transistor

(C) TRIAC

(D) Semi conductor diode

 

22-Resultant flux of 3 phase induction motor is:

(A) (√3/2)φm

(B) (3/2)φm

(C) 3 φm

(D) 2 φm

 

23-Which has negative temperature coefficient resistance?

(A) Copper

(B) Aluminium

(C) Iron

(D) Carbon

 

24-Syncronous speed of a 3 phase, 4 pole, 50Hz induction motor is

(A) 1500 rpm

(B) 1440 rpm

(C) 3000 rpm

(D) 2880 rpm

 

25-Maximum number of electrons in valence shell of an atom is:

(A) 3

(B) 6

(C) 8

(D) 16

 

26-The following is Y class insulating material:

(A) Mica

(B) Cotton

(C) Porcelain

(D) Asbestos

 

27-Electric charge is equal to:

(A) It

(B) I/t

(C) I2t

(D) I2/t

 

28-Resonant frequency of an ac series circuit is:

(A) 1/2π(LC)1/2

(B) 1/4π(LC)1/2

(C) 1/4πLC

(D) 1/2πLC

 

29-1N 4007 is semi conductor diode. Here 1N represents:

(A) Forward current

(B) Voltage drop

(C) One layer

(D) One PN junction

 

30-Limiting temperature of F class insulating material:

(A) 225°C

(B) 105°C

(C) 120°C

(D) 155°C

 

ANSWERS:

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