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

Question : 6

Alternating current is converted to direct current by

a) dynamo

b) transformer

c) rectifier

d) motor

Question : 7 [UPPCS (Mains) 2015]

Which element is the best conductor of electricity?

a) Aluminium

b) Silver

c) Copper

d) Iron

Question : 8

Barrier potential of a p-n junction diode does not depend on

a) diode design

b) temperature

c) doping density

d) forward bias

Question : 9 [NDA]

The main power supply in India is at 220 V, whereas that in the US is at 110 V. Which one among the following statements in this regard is correct?

a) 110 V leads to lower power loss

b) 110 V is safer but more expensive to maintain

c) 110 V is safer and cheaper to maintain

d) 110 V works better at higher latitudes

Question : 10

When a fuse is rated 8A, it means

a) it has a resistance of 8 ohm

b) it will work only if current is 8A

c) it will not work if current is less than 8A

d) it will burn if current exceeds 8A