Two parallel wires carrying currents in the same direction attract each other because of

1. 1. Electric forces between them
   2. Potential difference between them
   3. Magnetic force between them
   4. Mutual inductance between them

An electric motor is used to convert _____.

1. 1. Mechanical energy into kinetic
   2. Electrical energy into mechanical energy
   3. Higher voltage to lower voltage
   4. Mechanical energy into electrical

When the door of an operating refrigerator is opened the temperature of the room will _____.

1. 1. Fall down immediately
   2. Increase
   3. Decrease
   4. Remain unchanged

On earth a moving body ordinarily comes to rest by itself because of the _____.

1. 1. Gravity
   2. Law of inertia
   3. Forces of friction
   4. Conservation of momentum

Air is completely removed from an electric bulb to prevent _____.

1. 1. Bursting of the bulb
   2. Loss of light due to absorption
   3. Oxidation of tungsten filament
   4. None of them

In refrigerator, cooling is produced by _____.

1. 1. the sudden expansion of a compressed gas
   2. the evaporation of a volatile liquid
   3. The ice which deposits on the freezer
   4. None of these

Tube light works on the principle of _____.

1. 1. Discharge of electricity through gases
   2. Heating effect of current
   3. Chemical effect of current
   4. Magnetic effect of current

When wind blows at high velocity, roof tops are blown off because pressure _____.

1. 1. Is exerted by air form outside
   2. Outside is more than inside the roof
   3. Inside is more than outside the roof
   4. Increase due to wind velocity

The silvered surface of thermos flask prevents transfer of heat by _____.

1. 1. Radiation
   2. Convection
   3. Conduction
   4. Reflection

When a constant force is applied to a body it moves with uniform _____.

1. 1. Speed
   2. Velocity
   3. Momentum
   4. Acceleration