71) At 100% relative humidity, wet bulb temperature, dry bulb temperature, dew point temperature and saturation temperature are equal.

72) Bell-Coleman cycle is a

73) Sulphur dioxide is extremely toxic and non-flammable.

74) The transfer of heat from one body to another takes place only when there is a temperature difference between the bodies.

75) Which of the following statement is correct for ammonia as a refrigerant?