A main switch in the main distribution board is present in :

1. a live wire
2. a neutral wire
3. a live as well as neutral wire
4. an earth wire

A conductor AB is kept along north south direction of the earth above a magnetic needle as shown below. When the key K is closed then:

1. the needle will not show any deflection.
2. the needle will deflect towards east.
3. the needle will turn in the opposite direction i.e. towards south.
4. the needle will deflect towards west.

If water absorbs 4000 joule heat to increase the temperature of 1 kg water through 1°C then the specific heat capacity of water is :

1. 4 Jkg^-1°C^-1
2. 400 Jg^-1°C^-1
3. 4 Jg^-1°C^-1
4. 4.2 Jg^-1°C^-1

Water is used in car radiators because :

1. it is a good conductor of heat.
2. it conducts heat faster as compared to the other substances and cools the engine quickly.
3. its specific heat capacity is very low.
4. its specific heat capacity is very high so it can cool the engine without a greater increase in its own temperature.