41. When heat energy of 1500 Joules, is supplied to a gas

at constant pressure 2.1 x 10⁵N/m² , there was an increase in its volume equal to 2.5 x 10^-3 m³. The increase in internal energy of the gas in Joules is

(a)  450                  (b)  525

(c)   975                     (d)  2025

Ans. c