same
lower
higher
✅ The correct answer is option C.
Heat Transfer
The refrigerant used in small-tonnage commercial machines (hermetically sealed units) is
ammonia
carbon dioxide
sulphur dioxide
R-12
✅ The correct answer is option C.
For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference ™ for parallel flow is __________ that for counter flow.
equal to
less than
greater than
✅ The correct answer is option A.
The atmospheric air at dry bulb temperature of 15°C enters a heating coil maintained at 40°C. The air leaves the heating coil at 25°C. The by-pass factor of the heating coil is
0.376
0.4
0.6
0.67
✅ The correct answer is option C.
The horizontal and non-uniformly spaced lines on a psychrometric chart indicates
dry bulb temperature
wet bulb temperature
dew point temperature
specific humidity
✅ The correct answer is option C.
The refrigerant after condensation process is cooled below the saturation temperature before throttling. Such a process is called
sub-cooling or under-cooling
super-cooling
normal cooling
none of these
✅ The correct answer is option A.
In a refrigeration system, the expansion device is connected between the
compressor and condenser
condenser and receiver
receiver and evaporator
evaporator and compres
✅ The correct answer is option C.
A human body feels comfortable when the heat produced by the metabolism of human body is equal to the
heat dissipated to the surroundings
heat stored in the human body
sum of (a) and (b)
difference of (a) and
✅ The correct answer is option C.
The process of undercooling is generally brought about by
circulating more quantity of cooling water through the condenser
using water colder than the main circulating water
employing a heat exchanger
any one of the above
✅ The correct answer is option D.