Explore topic-wise MCQs in Mechanical Engineering.

This section includes 9 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

Operating pressures of the refrigerants at the evaporator in the ascending order for any application are

A. R11, R12, R717, R22
B. R22, R717, R12, R11
C. R11, R12, R22, R717
D. R717, R22, R11, R12
Answer» B. R22, R717, R12, R11
2.

Chemical formula of R-22 is given by:

A. CCl4F
B. CCl2F2
C. CHCl2F
D. CHClF2
Answer» E.
3.

Chemical formula for ‘R22’ refrigerant:

A. Monochloro difluoro methane
B. Trichloro fluoro methane
C. Dichloro monofluoro methane
D. Dichloro difluoro methane
Answer» B. Trichloro fluoro methane
4.

Choose undesirable properties of a secondary refrigerants.

A. low freezing point
B. high viscosity
C. good stability
D. low temperature pressure
Answer» C. good stability
5.

How many chlorine atoms does the refrigerant R – 134a contain?

A. Eight
B. Seven
C. One
D. Nil
Answer» E.
6.

Environment friendly refrigerant R 134a is used in the new generation domestic refrigerators. Its chemical formula is

A. CHCIF2
B. C2CI3F3
C. C2CL2F4
D. C2H2F4
Answer» E.
7.

Environmental protection agencies advise against the use of chloro-fluoro-carbon refrigerants since they react with

A. water vapour and cause acid rain
B. plants and cause green house effect
C. oxygen and cause depletion
D. ozone layer
Answer» E.
8.

Partial pressure of water vapour at dew point temperature of moist air is 1.5 × 10-3 MPa. The barometric pressure is 0.1 MPa. The specific humidity of air is

A. 15.225 gm/kg da
B. 9.47 gm/kg da
C. 15.00 gm/kg da
D. 9.33 gm/kg da
Answer» C. 15.00 gm/kg da
9.

Moisture in Freon refrigeration system causes _____.

A. Ineffective refrigeration
B. High power consumption
C. Freezing automatic regulating valve
D. Corrosion of whole system
Answer» D. Corrosion of whole system