Heat Transfer
For gases, the thermal conductivity increases with temperature rise. For liquids, with increase in concentration, its thermal conductivity generally

Decreases
Remains unchanged
Increases exponentially
Increases

ANSWER DOWNLOAD EXAMIANS APP

Heat Transfer
The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a refrigerator (COP)R and the co-efficient of performance as a heat pump (COP)HP are

(COP)R = (COP)HP = 0.6
(COP)R = 2.5; (COP)HP = 1.5
(COP)R = (COP)HP = 2.5
(COP)R = 1.5; (COP)HP = 2.5

ANSWER DOWNLOAD EXAMIANS APP