A moment of couple has a tendency to rotate the body in an anticlockwise direction then that moment of couple is taken as:

1. positive
2. negative
3. maximum
4. zero

For burning of coal in a thermoelectric station, the energy conversion taking place is:

1. chemical to heat to mechanical
2. chemical to heat to mechanical to electrical
3. chemical to heat to light
4. heat to chemical to mechanical

A nucleus of an atom consists of 146 neutrons and 95 protons. It decays after emitting an alpha particle. How many protons and neutrons are left in the nucleus after an alpha emission?

1. protons = 93, neutrons = 144
2. protons = 95, neutrons = 142
3. protons = 89, neutrons = 144
4. protons = 89, neutrons = 142

Assertion: Infrared radiations travel long distances through dense fog and mist.

Reason: Infrared radiations undergoes minimal scattering in earth's atmosphere

1. both assertion and reason are true.
2. both assertion and reason are false.
3. assertion is false but reason is true.
4. assertion is true reason is false.