set 5 MCQ Questions & Answers Detailed Explanation

Question : 1

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 : 2

Consider the following statements regarding a motor car battery:

1. The voltage is usually 12 V.
2. Electrolyte used is hydrochloric acid.
3. Electrodes are lead and copper.
4. Capacity is expressed in ampere-hour.

a) 3 and 4

b) 1 and 2

c) 2 and 3

d) 1 and 4

Question : 3

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 : 4

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

Question : 5

Consider the following statements regarding electric fuse wire:

1. It has low melting point.
2. It has very high specific resistance.
3. It is connected in parallel with the electric circuit.

a) 1 and 2

b) 1 only

c) 1 and 3

d) 2 and 3

Question : 6

A compass which is allowed to move in a horizontal plane is taken to a geomagnetic pole. It

a) will stay in any position

b) will stay in north-south direction only

c) will stay in east-west direction only

d) None of these