electric current and magnetism - Category wise Question and Answer Practice Test with Solutions

Question : 16

For a transistor amplifier, the voltage gain

a) is high at high and low frequencies and constant in the middle frequency range

b) is low at high and low frequencies and constant at mid frequencies

c) remains constant for all frequencies

d) None of these

Question : 17

A fuse is used in mains electric supply as a safety device. Which one of the following statements about the fuse is correct?

a) It must have a low melting point

b) It is connected in parallel with the main switch

c) It is made mainly from silver alloys

d) It must have very high resistance

Question : 18

Transistors are essentially

a) current driven devices

b) voltage driven devices

c) power driven devices

d) resistance driven devices

Question : 19 [UPPCS (Mains) 2009]

A dynamo which is said to generate electricity actually acts as a

a) Converter of energy

b) Source of ions

c) Source of electric charge

d) Source of electrons

Question : 20

One way in which the operation of an n-p-n transistor differs from that of a p-n-p

a) the emitter junction injects minority carriers into base region of the p-n-p

b) the emitter injects holes into the base of the p-n-p and electrons into the base region n-p-n

c) the emitter junction is reverse biased in n-p-n.

d) the emitter injects holes into the base of n-p-n