VAPOUR REFRIGERATION SYSTEM
1. Heat is absorbed by the
refrigerant, during vapour compression refrigeration cycle in
(a) Compressor
(b) Condenser
(c) Evaporator
(d) Throttle valve
2. In a simple saturated vapour compression cycle, the refrigerant is in superheated condition
(a) before entering compressor
(b)
before entering condenser
(c) before entering throttle valve
(d) before entering evaporator
3. Sub-cooling is a process of cooling the refrigerant in vapour compression refrigeration system
(a) after compression
(b) before compression
(c) before Throttling
(d) none of the above
4. The order in which main components of vapour compression refrigeration system are used is
(a)
compressor-evaporator-condenser-throttle valve
(b) compressor-condenser-evaporator-throttle
valve
(c) compressor-throttle valve-
evaporator-condenser
(d) compressor-condenser-
throttle valve- evaporator
5. The oil separator is
incorporated in vapour compression refrigeration system
(a) between evaporator and
compressor
(b) between compressor
and condenser
(c) between condenser and Throttle
valve
(d) between throttle valve and
evaporator
6. In vapour compression refrigeration cycle the following data is available Heat rejected in condenser
=65 KW Work done in compressor = 10 kw, then COP( refrigerator) is
(a) 4.5
(b) 5.5
(c) 6.5
(d) not possible to find with the given data
7. Following results are tabulated
for vapour compression refrigeration cycle.
Enthalpy at suction = 190 kJ/kg
Enthalpy at discharge from
compressor = 210 kJ/kg
Enthalpy at exit from condenser = 80 kJ/kg , COP of cycle would be
(a)3.5
(b) 4.5
(c) 5.5
(d) 6.5
8. For simple saturated vapour compression refrigeration cycle operating between 5°C and 40°C, and the refrigerants being R-11, R-12, R-717 and R-22, the evaporator pressure is lowest for
(a) R-11
(b) R-12
(c) R-717
(d) R-22
9. With reciprocating compressor in
vapour compression refrigeration system, wet
compression is not desirable
because
(a) liquid trapped up in
the head of cylinder may damage the compressor valves
(b) COP of the cycle decreases
(c) volumetric efficiency of
compressor decreases
(d) mass flow rate per ton of
refrigerant increases
10. An ideal refrigerant should
have
(a) low latent heat of vaporization
(b) high critical
temperature
(c) high boiling point
(d) high specific volume of vapour
11. The refrigerant leaving
throttle valve is
(a) saturated liquid
(b) saturated vapour
(c) superheated vapour
(d) fraction as saturated
vapour and remainder as liquid
12. Freon group of refrigerants
(a) toxic
(b) inflammable
(c) non-toxic and non-inflammable
(d) highly toxic and inflammable
13. The leaks of refrigerant from a
cycle may be detected by
(a) halide torch test
(b) sulphur candle test
(c) soap and water test
(d) any of the above
14. During compression in a vapour compression cycle the refrigerant is super heated
(a) work done is
increased
(b) C.O.P is increased
(c) Work done is reduced
(d) Refrigerating effect is reduced
15. Heat is rejected by the
refrigerant, during vapour compression refrigeration cycle in
(a) Compressor
(b) Condenser
(c) Evaporator
(d) Throttle valve
16. Wet compression vapour
compression refrigeration cycle means
(a) Vapour compression
takes place in wet region
(b) Vapour compression in dry
region, but evaporation in wet region
(c) vapour compression in wet
region, but leaves in superheated region
(d) None of the above
