Q.1

The dehumidification process, on the psychrometric chart, is shown by

  • horizontal Sine
  • vertical line
  • inclined line
  • curved line
Q.2

The human body feels comfortable when the heat stored in the body is

  • positive
  • negative
  • zero
  • none of these
Q.3

Most air cooled condensers are designed to operate with a temperature difference of

  • 5°C
  • 8°C
  • 14°C
  • 22°C
Q.4

A reversible engine has ideal thermal efficiency of 30%. When it is used as a refrigerating machine with all other conditions unchanged, the coefficient of performance will be

  • 1.33
  • 2.33
  • 3.33
  • 4.33
Q.5

In aqua-ammonia absorption refrigeration system, incomplete rectification leads to accumulation of water in

  • condenser
  • evaporator
  • absorber
  • none of these
Q.6

Which of the following refrigerant has the lowest boiling point?

  • Ammonia
  • Carbon dioxide
  • Sulphur dioxide
  • R-12
Q.7

The most commonly used method for the design of duct size is the

  • velocity reduction method
  • equal friction method
  • static regain method
  • dual or double method
Q.8

In counter-current flow heat exchangers

  • both the fluids at inlet are in their hottest state
  • both the fluids at inlet are in their coldest state
  • both the fluids at exit are in their hottest state
  • one fluid is coldest and the other is hottest at inlet
Q.9

In larger industrial and commercial reciprocating compression systems, refrigerent widely used is

  • ammonia
  • carbon dioxide
  • sulphur dioxide
  • R-12
Q.10

Radiation is the process of heat transfer in which heat flows from a __________ , in a straight line, without affecting the intervening medium.

  • cold body to hot body
  • hot body to cold body
  • smaller body to larger body
  • larger body to smaller body
Q.11

The heating of air, without any change in its specific humidity, is known as sensible heating.

  • True
  • False
Q.12

The freezing point of sulphur dioxide is

  • -56.6°C
  • -75.2°C
  • -77.7°C
  • -135.8°C
Q.13

The value of the wave length for maximum emissive power is given by

  • Kirchhoff's law
  • Stefan's law
  • Wein's law
  • Planck's law
Q.14

In a domestic vapour compression refrigerator, the refrigerant commonly used is

  • CO2
  • Ammonia
  • R-12
  • all of these
Q.15

The vertical and uniformly spaced lines on a psychrometric chart indicates

  • dry bulb temperature
  • wet bulb temperature
  • dew point temperature
  • specific humidity
Q.16

A Bell Coleman refrigerator working on dense air system as compared to open air system, for the same range of temperature, results in __________ power per tonne of refrigeration.

  • same
  • lower
  • higher
Q.17

Which of the following refrigerant is highly toxic and flammable?

  • Ammonia
  • Carbon dioxide
  • Sulphur dioxide
  • R-12
Q.18

In a psychrometric chart, specific humidity (moisture content) lines are

  • vertical and uniformly spaced
  • horizontal and uniformly spaced
  • horizontal and non-uniformly spaced
  • curved lines
Q.19

During sensible cooling of air, the relative humidity increases.

  • Yes
  • No
Q.20

In a psychrometric chart, specific humidity (moisture content) lines are

  • vertical and uniformly spaced
  • horizontal and uniformly spaced
  • horizontal and non-uniformly spaced
  • curved lines
Q.21

The ratio of the energy absorbed by the body to the total energy falling on it, is called

  • absorptive power
  • emissive power
  • emissivity
  • none of these
Q.22

The amount of heat flow through a body by conduction is

  • directly proportional to the surface area of the body
  • directly proportional to the temperature difference on the two faces of the body
  • inversely proportional to the thickness of the body
  • all of the above
Q.23

A condenser is used in the __________ pressure side of a refrigerating system.

  • low
  • high
Q.24

The temperature of air recorded by a thermometer, when it is not effected by the moisture present in the air, is called

  • wet bulb temperature
  • dry bulb temperature
  • dew point temperature
  • none of these
Q.25

The power per tonne of refrigeration is

  • 3.5/C.O.P.
  • C.O.P/3.5
  • 3.5 x C.O.P.
  • none of these
Q.26

The capillary tube, as an expansion device, is used in

  • domestic refrigerators
  • water coolers
  • room air conditioners
  • all of these
Q.27

The unit of Stefan-Boltzmann constant is

  • Watt/mK
  • Watt/m2K2
  • Watt/m2K4
  • Watt/mK2
Q.28

The expression Q = ρ AT4 is called

  • Fourier equation
  • Stefan-Boltzmann equation
  • Newton-Rikhmann equation
  • Joseph-Stefan equation
Q.29

During sensible heating of air __________ decreases.

  • wet bulb temperature
  • relative humidity
  • dry bulb temperature
  • specific humidity
Q.30

The heat transfer from a hot body to a cold body is directly proportional to the surface area and difference of temperatures between the two bodies. This statement is called

  • First law of thermodynamics
  • Newton's law of cooling
  • Newton's law of heating
  • Stefan's law
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