(a) ag,ah and as are positive (b) ag, ah and as are negative. (c) ag and ah are negative and as is positive. d) ag is negative and ah and as are positive, the c

(a) AG,AH and AS are poSitive (b) AG, AH and AS are negative. (c) AG and AH are negative and AS is positive. d) AG is negative and AH and AS are positive, The coefficient of performance ofa perfect refrigerator working reversibly between the temperatureT and T is given by 15 GATE 20041