MCQ
2181. According to Kelvin-Planck statement, it is impossible to construct a device operating on a cycle which transfers heat from-
Low pressure heat reservoir to high pressure reservoir
Low temperature heat reservoir to high temperature reservoir
High pressure heat reservoir to low pressure reservoir
High temperature heat reservoir to low temperature reservoir
2182. The COP of the vapour absorption cycle as compared to vapour compression cycle is—
higher
lower
same
none of above.
2183. During a refrigeration cycle heat is rejected by the refrigerant in a-
compressor
condenser
evaporator
expansion valve
2184. Which of the following refrigerant is highly toxic and flammable?
sulphur dioxide
Freon-12
Ammonia
Carbon dioxide
2185. In an isothermal process-
There is no change in enthalpy
There is no change in internal energy
There is no change in temperature
All of these
2186. According to kinetic theory of gases, the absolute zero temperature is attained when-
Volume of the gas is zero
Pressure of the gas is zero
Kinetic energy of the molecules is zero
Specific heat of gas is zero
2187. The capacity of a domestic refrigerator is the range of-
0.1 to 0.3 TR
1 to 3 TR
3 to 5 TR
5 to 7 TR
2188. Zeroth law of thermodynamics-
Deals with conversion of mass and energy
Deals with reversibility and irreversibility of process
States that if two systems are both in equilibrium with a third system, they are in thermal equilibrium with each other
Deals with heat engines
2189. Temperature of a gas is produced due to-
Its heating value
Kinetic energy of molecules
Repulsion of molecules
Attraction of molecules
2190. Measurement of temperaturę is based on-
Thermodynamic properties
Zeroth law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
2191. A standard ice point temperature corresponds to the temperature of-.
water at 0°C
ice at-4°C
solid and dry ice
mixture of ice and water under equilibrium conditions
2192. A condenser of refrigeration system rejects heat at the rate of 120kW while its compressor consunes a power of 30 kW. The coefficient of performance of the system would be-
1/4
3
4
1/3
2193. The temperature of ammonia after compression in a vapour compression system is-
20 to 50°C
70 to 100°C
50 to 70°C
none of these
2194. Which of the following refrigerant has the lowest freezing point?
R-11
R-22
R-12
Ammoma
2195. A good refrigerant should have-
high latent heat of vaporisation and low freezing point
high operating pressures and low freezing point
high specific volume and high latent heat of vaporisation
low COP and low freezing point
2196. A domestic refrigerator has the co- efficient of performance-.
equal to 10
less than 10
more than 10
none
2197. Kelvin-Planck's law deals with-
Conservation of heat
Conservation of work
Conversion of heat into work
Conversion fo work into heat
2198. A refrigerant with the highest critical pressure is-
R-11
R-22
R-12
Ammonia
2199. Which of the following variables controls the physical properties of a perfect gas?
Pressure
Temperature
Volume
All of the above
2200. Superheated vapour behaves—
Exactly as gas
As steam
As ordinary vapour
Approximately as a gas