One end of an insulating U tube is sealed using insulating material. A mono atomic gas at temperature 300 K occupies 20 cm length of the tube as shown. The level of mercury on two sides of the tube differ by 5 cm. The other end of the tube is open to atmosphere. Area of cross section of the tube is uniform and is equal to `0.01 m^(2)`. The gas in the tube is heated by an electric heater so as to raise its temperature to 562.5 K. Assume that no heat is conducted to mercury by the gas.
(a) Find the final length of the gas column.
(b) Find the amount of heat supplied by the heater to the gas.