The tubes in a heat exchanger have the following dimensions; inside diameter 25mm, outside diameter 30mm, length 5.0m. they are made of steel with a thermal conductivity of 50 w/mk. the values of the inside and outside heat transfer coefficients are 1000 w/m2k and 2000 wim2k respectively. the fouling resistances are 0.0001 m2k/w on the inside and 0.0005 m2k/w on the outside taking the overall temperature difference as 50°c, calculate the rate of heat transfer for one tube using (a) the overall heat transfer coefficient based on the inside area, (b) the overall heat transfer coefficient based on the outside area.