Heat Transfer, Refrigeration and Air Conditioning Questions

• Bell-Coleman cycle is a
• Which of the following statement is correct?
• The sulphur sticks, in case of leakage of ammonia refrigerant, gives white smoke.
• The transfer of heat from one body to another takes place only when there is a temperature difference between the bodies.
• During gas charging in an ammonia vapour compression system, the connection is made at the compressor outlet.
• The water, alcohol and ammonia have same refrigerating effect at different altitudes.
• The wet bulb temperature at 100% relative humidity is __________ dew point temperature.
• Thermal diffusivity of a substance is given by (where h = Thermal diffusivity, ρ = Density of substance, S = Specific heat, and k = Thermal conductivity)
• The counter-current flow heat exchanger can transfer __________ heat than parallel flow heat exchanger.
• The natural convection air cooled condensers are used in
• The conditioned air supplied to the room must have the capacity to take up
• A pressure gauge on the discharge side of a refrigerant compressor reads too high. The reasons will be
• Which of the following would lead to a reduction in thermal resistance?
• The process, generally used in winter air-conditioning to warm and humidity the air, is called
• Which of the following refrigerant has the highest freezing point.
• In mechanical refrigeration system, the refrigerant occurs as liquid between condenser and expansion valve.
• The coefficient of performance of electrolux refrigerator is the ratio of
• The freon group of refrigerants are
• The sensible heat gain is due to the __________ difference between the fresh air and the air in space.
• At 100% relative humidity, wet bulb temperature, dry bulb temperature, dew point temperature and saturation temperature are equal.