set 5 MCQ Questions & Answers Detailed Explanation

Question : 1

Electric motors operating at low voltages tend to burn out because

a) They draw heat proportional to $v^2$

b) They draw more current which is inversely proportional to the voltage

c) They draw more current which is inversely proportional to the square root of the voltage

d) Low voltage sets in electrical discharge

Question : 2

Domestic electrical wiring is basically a

a) Combination of series and parallel connections

b) Series connection

c) Parallel connection

d) Series connection within each room and parallel connective elsewhere

Question : 3

To obtain a p-type germanium semiconductor, it must be doped with

a) antimony

b) indium

c) arsenic

d) phosphorus

Question : 4

Consider the following statements :

1. The strength of magnetic field of a permanent magnet decreases with the increase in temperature.
2. A permanent magnet can be demagnetised by beating it.
3. A charged particle moving parallel to direction of magnetic field experiences a force.

a) 1 and 3

b) 1 and 2

c) 2 and 3

d) 1, 2 and 3

Question : 5

Choke coil works on the principle of

a) self induction

b) mutual induction

c) transient current

d) wattless current

Question : 6

If a bulb of 100 watt burns for 10 hours, the expenditure of electricity will be

a) 10 units

b) 0-1 unit

c) 1 unit

d) 100 units