set 5 MCQ Questions & Answers Detailed Explanation

Question : 1

p-n junction diode works as a insulator, if connected

a) in forward bias

b) in reverse bias

c) to A.C.

d) None of these

Question : 2

An object is kept 5 cm in front of a concave mirror of focal length 15 cm. What will be the nature of the image?

a) Real, not magnified

b) Virtual, not magnified

c) Virtual, magnified

d) Real, magnified

Question : 3

Alternating current is converted to direct current

a) By Transformer

b) By Dynamo

c) By Motor

d) By Rectifier

Question : 4

The heating element of an electric heater should be made with a material, which should have

a) high specific resistance and low melting point

b) low specific resistance and low melting point

c) high specific resistance and high melting point

d) low specific resistance and high melting point

Question : 5

The part of a transistor which is most heavily doped to produce large number of majority carriers is

a) base

b) collector

c) emmiter

d) can be any of the above three

Question : 6

When current is passed through an electric bulb, its filament glows, but the wire leading current to the bulb does not glow because

a) the leading wire has more resistance than the filament

b) the leading wire has less resistance than the filament

c) less current flows in the leading wire as compared to that in the filament

d) filament has coating of fluorescent material over it