REFRIGERATION AND AIR CONDITIONING

REFRIGERATION AND AIR CONDITIONING 

1. The compressor motor in

a hermetically sealed compressor

 is cooled by ............

a) Water

b) Air

c) Refrigerant

d) Nitrogen

Answer:- b) Air

2. The screw compressors can be

used for wet compression with

refrigerant -
a)  R134a

b)  R12

c)  NH3

d)  Water

Answer:- c)  NH3

3. For large capacity and high

volume flow rate the suitable

compressor is ............
a)  Centrifugal

b)  Reciprocating      

c)  Screw

d)   Scroll

Answer:- a)  Centrifugal

4. The main components of a

centrifugal compressor are .....

a)  Eye

b)  Impeller

c)  Diffuser

d)  Both (a) & (b)

Answer:- d)  Both (a) & (b)

5. The slip in case of three

phase induction motor is in

the range of.........

a) 0.5% to 5%

b) 2% to 10%

c) 10% to 15%

d) 15% to 20%

Answer:- a) 0.5% to 5%

6. High starling torque induction

motors for compressors are

used with .............

a)  Capillary tube      

b)  Condenser

c)  Float valves

d)  None of these

Answer:- d) None of these

7. The relationship between

rotor speed 'N' frequency 'F'and no.

of poles 'P' is given by
the relation ...........

a)  N=120t7P

b)  PN=120/f

c)  f=120N/P

d)  N=l20P/f

Answer:- a)  N=120t7P

8. The function of condenser

 in a refrigeration system is ..........

a) To cool surrounding air

b) To cool products or space

c) To condense the superheated

vapor refrigerant discharged by

the compressor

d) To condense the refrigerant

vapour entering the compressor

Answer:- c) To condense the superheated

vapor refrigerant discharged by

the compressor

9. Domestic refrigeration work on .....

a) Vapour compression cycle

b) Vapour absorption

c) Otto cycle

d) None of these

Answer:- a) Vapour compression cycle

10. Liquid receiver is installed in -

a) Suction line

b) Discharge line

c) Liquid line

d) Expansion line

Answer:- c) Liquid line