MCQ
2161. For better COP of refrigerator, the pressure range corresponding to temperature in evaporator and condemer must be-
small
equal
high
anything
2162. Domestic refrigerator working on vapour compression cycle uses the following type of expansion device-
electrically operated throttling valve
manually operated valve
thermostatic valve
capillary tube
2163. The term N.T.P. stands for-
Nominal temperature and pressure
Natural temperature and pressure
Normal temperature and pressure
Normal thermodynamic practice
2164. Refrigeration in aeroplanes usually employs the following refrigerant-
Freon-11
Air
Freon-22
Ammonia
2165. One of the purposes of subcooling the liquid refrigerant is to-
reduce compressor overheating
reduce compressor discharge temperature
increase cooling effect
ensure that only liquid and not the vapour enters the expansion (throttling) valve
2166. Which of the following is the extensive property of a themodynamic system?
Pressure
Volume
Temperature
Density
2167. Which of the following is not the intensive property?
Pressure
Temperature
Density
Heat
2168. Highest temperature refrigeration cycle should be encountered In near critical temperature of refrigerant--
above critical temperature
at critical temperature
much below critical temperature
none
2169. Which of the following quantities is not the property of the system?
Pressure
Temperature
Specific volume
Heat
2170. Heat and work are-
Point functions
System properties
Path functions
Intensive properties
2171. The relative coefficient of performance is-
actual COP/theoretical COP
theoretical COP/actual COP
actual COP x theoretical COP
1-actual COP x theoretical COP
2172. The higher temperature in compression cycle occurs at-
receiver
expansion valve
evaporator
compressor discharge
2173. Extensive property of a system is one whose value-
Depends on the mass of the system like volume
Does not depend on the mass of the system, like temperature, pressure etc.
Is not dependent on the path followed but on the state
Is dependent on the path followed and not on the state
2174. The bank of tubes at the back of domestic refrigerator are-
condenser tubes
evaporator tubes
refrigerant cooling tubes
capillary tubes
2175. Absorption system normally uses the following refrigerant-
Freon-11
ammonia
Freon-22
CO
2176. Which of the following cycles uses air as the refrigerant?
Ericsson
Carmot
Stirling
Bell-coleman
2177. In refrigerator, liquid receiver is required between condenser and flow controlling device, if quantity of refrigerant for system is-
less than 2kg
more than or equal to 3.65kg
more than 10kg
there is no such consideration
2178. Vapour compression refrigeration is some what like-.
Camot cycle
Rankine cycle
reversed Canet cycle
none of the above
2179. Presence of moisture in a refrigerant affects the working of--
compressor
condemer
evaporator
expansion valve
2180. Ammonia-absorption refrigeration cycle requires--
very litle work input
maximum work, input
nearly same work input as for vapour
compression cycle zero work input