Compressors, Gas Turbines and Jet Engines MCQs

Question 1

The air power of the compressor is also known as

Accepted Answer

Indicated power

Answer

Brake power

Answer

Frictional power

Answer

None of these

Question 2

To avoid moisture troubles, the compressed air main line should

Accepted Answer

Drop gradually towards the point of use

Answer

Rise gradually towards the point of use

Answer

Be laid vertically

Answer

Be laid exactly horizontally

Question 3

The ratio of the discharge pressure to the inlet pressure of air is called

Accepted Answer

Compression ratio

Answer

Expansion ratio

Answer

Compressor efficiency

Answer

Volumetric efficiency

Question 4

A machine used to raise the pressure of air is called

Accepted Answer

Compressor

Answer

Gas turbine

Answer

I.C engine

Answer

Air motor

Question 5

The efficiency of jet engine is

Accepted Answer

Higher at high altitudes

Answer

Lower at low speed

Answer

Same at all altitudes

Answer

Higher at high speed

Question 6

The volume of air delivered in a medium capacity air compressor per unit time is

Accepted Answer

0.15 to 5 m3/s

Answer

0.1 to 1.2 m3/s

Answer

Above 5 m3/s

Answer

None of these

Question 7

The inter-cooler pressure, for minimum work required, for a two stage reciprocating air compressor, is given by (where p1 = Intake pressure of air, p2 = Inter-cooler pressure and p3 = Delivery pressure of air)

Accepted Answer

$${{	ext{p}}_2} = \sqrt {{{	ext{p}}_1} 	imes {{	ext{p}}_2}} $$

Answer

$${{	ext{p}}_2} = {{	ext{p}}_1} 	imes {{	ext{p}}_3}$$

Answer

$${{	ext{p}}_2} = \frac{{{{	ext{p}}_1}}}{{{{	ext{p}}_3}}}$$

Answer

$${{	ext{p}}_2} = \frac{{{{	ext{p}}_3}}}{{{{	ext{p}}_1}}}$$

Question 8

Atmospheric pressure is 1.03 kg/cm and vapour pressure is 0.03 kg/cm. The air pressure will be

Accepted Answer

1.00 kg/cm2

Answer

1.03 kg/cm2

Answer

1.06 kg/cm2

Answer

0.53 kg/cm2

Question 9

For perfect intercooling in a three stage compressor

Accepted Answer

$$\frac{{{{	ext{p}}_2}}}{{{{	ext{p}}_1}}} = \frac{{{{	ext{p}}_3}}}{{{{	ext{p}}_2}}} = \frac{{{{	ext{p}}_4}}}{{{{	ext{p}}_3}}}$$

Answer

$$\frac{{{{	ext{p}}_3}}}{{{{	ext{p}}_1}}} = \frac{{{{	ext{p}}_4}}}{{{{	ext{p}}_2}}}$$

Answer

$${{	ext{p}}_1}{{	ext{p}}_2} = {{	ext{p}}_3}{{	ext{p}}_4}$$

Answer

$${{	ext{p}}_1}{{	ext{p}}_3} = {{	ext{p}}_2}{{	ext{p}}_4}$$