# CIL MT Mechanical Previous Exam Question Part-1

## CIL MT Mechanical Previous Exam Question Part-1

### Coal India Ltd. Previous Exam Questions

This Test is based on Previous CIL MT Exam Paper. Helpful for upcoming exams. In this test only Thermal Engineering related questions are mentioned, rest part will be posted in next pos

#### Useful for CIL MT (Mechanical) and other PSUs Exams.

1. Which of the following is the lowest temperature?
a. Triple point of water
b. Boiling point of Oxygen
c. Triple point of Oxygen
d. Freezing point of gold

2. In diesel engine mixing of fuel and air occurs in?
a. Fuel pump
b. injector
c. inlet manifold
d. engine cylinder

3. Thermal efficiency of a spark ignition engine at full load will be around
a. 10-20%
b. 30-35%
c. 60-75%
d. 90-95%

4. The turbulence in diesel engine ensures
a. Higher volumetric efficiency
b. Higher fuel consumption
c. Intimate mixing of fuel and air
d. Reduce engine vibrations

5. Which of the following process is not a part of the dual cycle?
b. Constant volume expansion
c. Isothermal expansion
d. Constant pressure expansion

6. Which of the following part is exclusive to diesel engines?
a. Air cleaner
b. Fuel injector
c. Starter

7. A diesel engine while in operation suddenly show loss of power, the probable cause cannot be
a. Clogging of air cleaner
b. Restriction in exhaust
c. Slippage of clutch
d. poor compression ratio

8. A large plane wall consists of two layers of solid materials each 1cm thick. The surface temperature of layer ‘’A’’ is T, and the temperature on the surface of layer ‘’B’’ is T2. The thermal conductivity of layer A is kA  and of layer B is kB . Assuming no thermal contact resistance, temperature Tx of the interface where A and B are in contact is.
a. Tx = (T1 + T2 )/2
b. Tx = (KA /KB) (T 1+ T2) /2
c. TX = [(KA/KB) T1+T2]/[(KA/KB)+1]
d. TX=[(KA/KB)(T1+T2)]/4

9. Natural convection heat transfer is produced by buoyancy force. Section views of the material having horizontal flat surface and losing heat by natural convection to still air losing heat by nature convection to still air are shown.
Surface 1 and 2 are at 100 degree Celcius and have air temperature of 0 degree Celcius
Surface 3 and 4 are at 0 degree Celcius and have air temperature of 100 degree Celcius
In term of ability to transfer heat by natural convection, which of the following is true?
a.1>2 and 3>4
b.1<2 and 3<4
c. 2>4 and 3< 2
d. 3> 2 and 4> 1

10. In the selection of an opaque surface to act as a collector of solar energy, it would be desirable for the surface to have which of the following sets of characteristics?
(a) Absorbtivity for radiation in the visible spectrum= high
Emissivity for how temperature radiation= low
Convective heat transfer coefficient = low

(b) Absorbtivity for radiation in the visible spectrum=high
emissivity for how temperature radiation =high
convective heat transfer coefficient = low

(c) Absorbtivity for radiation in visible spectrum = low
Emissivity for how temperature= high
Convection heat transfer coefficient= high

(d) Absorbtivity for radiation in the visible spectrum = low
Emissivity for how temperature radiation = high
Convective heat transfer coefficient = high

Check it: CIL MT detailed Syllabus
CIL MT (Mechanical) Previous Paper-2

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