Deck 14: Condensers and Heat Transfer in Refrigeration and Air Conditioning Systems

Question 1

In traditional Refrigerators in home appliances, what is the type of condenser used?

A)natural convection type
B)forced convection type
C)furnace type
D)rotary condensers

Answer 1

natural convection type

Question 2

In traditional Air conditioners in home appliances, what is the type of condenser used?

A)natural convection type
B)forced convection type
C)flash type
D)rotary condensers

Answer 2

forced convection type

Question 3

In evaporative condensers, ___________ used to extract heat from the condensing refrigerant.

A)air is
B)both air and water are
C)water is
D)either air or water is

Answer 3

both air and water are

Question 4

Evaporative condensers combine the features of a _____________ in a single unit.

A)cooling tower and water-cooled condenser
B)falling tower and water-cooled condenser
C)cooling tower and air condenser
D)rising film tower and water-cooled condenser

Question 5

Evaporative condensers are used in places where water is _________

A)scarce
B)plenty
C)moderately available
D)sufficient

Question 6

What is the meaning of heat rejection ratio (HRR) of a condenser?

A)ratio of heat rejected to the heat absorbed
B)ratio of heat absorbed to the heat rejected
C)ratio of heat required to the heat lost
D)ratio of heat wasted in a cycle to the heat absorbed

Question 7

What is the relation between heat rejection ratio (HRR) and Coefficient of performance (COP)?

A)hrr = 1 + 1/cop
B)hrr = 1+ cop
C)hrr = cop/2
D)hrr = 1/cop

Question 8

Which type of fins are the most commonly used fin type in condensers?

A)annular fin
B)plate type fins
C)tube fin
D)extended double pipe

Question 9

Shell and coil type condensers have a capacity at around ________

A)10 tr
B)20 tr
C)30 tr
D)50 tr

Question 10

Double pipe water cooling condensers have a capacity at around ________

A)10 tr
B)20 tr
C)30 tr
D)50 tr

Question 11

If there is a decrease in viscosity, the heat transfer coefficient ____________

A)increase
B)decrease
C)remains same
D)becomes zero

Question 12

An increase in diameter means a _________ heat transfer coefficient.

A)larger
B)smaller
C)zero
D)infinite

Question 13

why is an analyser-rectifier combination is used in absorption refrigeration cycle?

A)to increase the amount of water vapour in ammonia vapour
B)to decrease the amount of water vapour in ammonia vapour
C)to eliminate the water vapour from ammonia vapour
D)all of the mentioned

Question 14

The vapour going to condenser is ____ in temperature and ____ in ammonia.

A)higher, less
B)higher, richer
C)lower, less
D)lower, richer

Question 15

Water is used as a ____ in air conditioning units.

A)absorbent
B)refrigerant
C)absorbent and refrigerant
D)none of the mentioned

Question 16

The COP of absorption refrigeration system is

A)low
B)high
C)equal to that of vapour compression refrigeration system
D)none of the mentioned

Question 17

The wet bulb temperature is the ____ temperature recorded by moistened bulb.

A)lowest
B)highest
C)atmospheric
D)none of the mentioned

Question 18

When unsaturated air flows over a sheet of water in an insulated chamber

A)specific humidity of air decreases
B)the water evaporates
C)both air and water are cooled during evaporation
D)all of the mentioned

Question 19

When humidity ratio of air ____ air is said to be dehumidified.

A)increases
B)decreases
C)remains constant
D)none of the mentioned

Question 20

Cooling towers are rated in terms of

A)approach
B)range
C)both of the mentioned
D)none of the

Question 21

A nozzle used to send fluid in coherent stream is called as______________      

A)jet
B)high velocity nozzle
C)every nozzle sends fluid in coherent stream
D)none of the mentioned

Question 22

In fountains the type of nozzle used is

A)none of the mentioned
B)turbulent jet
C)high speed nozzle
D)laminar jet

Question 23

The supersaturated flow of steam through a nozzle as compared to a stable flow, the available heat drop______________      

A)increases
B)decreases
C)is unpredictable
D)remains same

Question 24

The ratio of the useful heat drop to the isentropic heat drop is called______________      

A)condenser efficiency
B)nozzle efficiency

Question 25

Critical pressure ratio is ratios of pressures at______________discharge.

A)minimum
B)none of the mentioned
C)optimum
D)maximum