(a) Define specific resistance.

(b) What happens to the specific resistance of a conductor if its length is doubled?

(c) Name a substance whose specific resistance remains almost unchanged with the increase in its temperature.

(a) State the principle of calorimetry.

(b) Name the material used for making a calorimeter.

(c) Write one characteristic property of the material chosen for making a calorimeter.

(a) Which nuclear radiation will travel undeviated in an electric field?

(b) How can one stop the radiations escaping from a nuclear reactor in a nuclear power plant?

(c) Name one internal source of background radiations.

Calculate the total amount of heat energy required to melt 200 g of ice at 0°C to water at 100°C.

(Specific latent heat of ice = 336 J g^-1, specific heat capacity of water = 4.2 J g^-1°C^-1)