391. An electrolux refrigerator is called a __________ absorption system.
[A]. single fluid
[B]. two fluids
[C]. three fluids
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✅ The correct answer is option C.
Heat Transfer, Refrigeration and Air Conditioning MCQs
392. Degree of saturation or percentage humidity is
[A]. the mass of water vapour present in 1 m3 of dry air
[B]. the mass of water vapour present in 1 kg of dry air
[C]. the ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure.
[D]. the ratio of actual mass of water vapour in a given volume of moist air to the mass of water vapour in the same volume of saturated air at the same temperature and pressure
✅ The correct answer is option C.
393. Reynolds number (RN) is given by (where h = Film coefficient, l = Linear dimension, V = Velocity of fluid, k = Thermal conductivity, t = Temperature, ρ = Density of fluid, cp = Specific heat at constant pressure, and μ = Coefficient of absolute viscosity)
[A].
[B].
[C].
[D].
✅ The correct answer is option C.
394. Thermal diffusivity is a
[A]. function of temperature
[B]. physical property of a substance
[C]. dimensionless parameter
[D]. all of these
✅ The correct answer is option B.
395. The temperature of ammonia after compression in a vapour compression system is
[A]. 20 to 50° C
[B]. 50 to 70° C
[C]. 70 to 110° C
[D]. none of these
✅ The correct answer is option C.
396. A refrigeration system
[A]. removes heat from a low temperature body and delivers it to a high temperature body
[B]. removes heat from a high temperature body and delivers it to a low temperature body
[C]. rejects energy to a low temperature body
[D]. none of the above
✅ The correct answer is option A.
397. While designing the refrigeration system of an aircraft, the prime consideration is that the
[A]. system has high C.O.P.
[B]. power per TR is low
[C]. mass of refrigerant circulated in the system is low
[D]. mass of the refrigeration equipment is low
✅ The correct answer is option D.
398. In aqua-ammonia and Lithium-bromide water absorption refrigeration systems, the refrigerants are respectively
[A]. water and water
[B]. water and lithium bromide
[C]. ammonia and lithium bromide
[D]. ammonia and water
✅ The correct answer is option D.