MCQ on refrigeration and Airconditioning for JE exam part 3
| 21. Bell-Coleman cycle is applicable to (a) Vapour compressor refrigeration (b) Vapour absorption refrigeration (c) Air refrigeration (d) All of them |
| Ans : (c) |
| 22. In a refrigeration cycle, if vapour is super heated after compression then it is called.......... (a) dry compression (b) wet compression (c) subcooling (d) vapour compression |
| Ans : (a) |
| 23. 1 ton of refrigeration implies heat transfer at the rate of (a) 210 kJ/min (c) 1000 kJ/hr |
(d) 2 kJ/hr
| Ans : (a) |
| 24. Ratio of refrigerating effect to the work supplied is called (a) Coefficient of Performance (COP) (b) Energy Performance Ratio (EPR) (c) Efficiency/o#elee (d) Relative COP |
| Ans : (a) |
| 25. A refrigerant mostly used for reciprocating compressor is |
| (a) NH3 (b) Freon–12 |
(d) Freon–22
| Ans : (b) |
| 26. Efficiency of a Carnot engine is 75%. If the cycle direction is reversed, COP of the reversed Carnot cycle is (a) 1.33 (c) 0.33 |
(d) 1.75
| Ans : (c) |
| 27. R–12 is preferred over R–22 in deep freezer, because (a) It has lower operating pressure. (b) It gives higher COP. (c) It is miscible with oil over a large range of temperature. (d) All of the above |
| Ans : (c) |
| 28. In an air craft refrigeration system the pressure at the cooling turbine outlet is equal to (a) Ambient pressure (b) Cabin pressure (c) Pressure at inlet to compressor mebheer (d) None of the above |
| Ans : (b) |
| 29. An undesirable property of a refrigerant is : (a) High critical temperature (b) High latent heat of vapourisation (c) High boiling point (d) Low specific heat of liquid |
| Ans : (c) |
| 30. A substance is said to be volatile if it has ........... (a) lower melting point (b) higher boiling point (c) high vapour pressure (d) high surface tension |
| Ans : (c) |
Water 0.03 atm
Ethyl alcohol 0.08 atm
Diethyl ether 0.7 atm
Bromine 0.3 atm