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.

To study the age of excavated material of archaeological significance we study the rate of decay of an isotope of :

1. Uranium
2. Cobalt
3. Carbon
4. Chlorine

The diagram below shows a magnetic compass kept closer to a coil AB wound around a hollow cylindrical cardboard :

(a) After studying the circuit and the magnetic compass carefully, state whether the switch S₁ is open or closed.

(b) How did you arrive at the conclusion in (a)?

(c) What is the purpose of placing the magnetic compass in the above setup?