GATE Mechanical Engineering Practice Quiz

Question 1

In an ideal vapor-compression refrigeration cycle using R-134a, the refrigerating effect is increased while keeping the compressor work unchanged. What happens to the coefficient of performance (COP) of the refrigerator?

Accepted Answer

COP increases

Question 2

In a simple vapor-compression refrigeration system, the throttling device is ideally modeled as a process with which property remaining constant?

Accepted Answer

Enthalpy

Question 3

A vapor-compression refrigerator operates between an evaporator temperature of -10°C and a condenser temperature of 30°C. Assuming a reversed Carnot refrigerator for comparison, the maximum possible COP is approximately

Accepted Answer

6.58

Question 4

Moist air at 1 atm has dry-bulb temperature 35°C and partial pressure of water vapor 2.5 kPa. If the saturation pressure of water vapor at 35°C is 5.62 kPa, the relative humidity is closest to

Accepted Answer

0.445 or 44.5%

Question 5

For a reversed Carnot refrigerator operating between a refrigerated space at temperature TL and surroundings at TH, the COP is

Accepted Answer

TL/(TH - TL)

GATE Mechanical Engineering

Students preparing for GATE Mechanical Engineering

Quizzes