One stroke
Two strokes
Four strokes
Three strokes

## Compressors, Gas Turbines and Jet Engines For a two stage compressor, if index of compression for higher stage is greater than index of compression for lower stage, then the optimum pressure as compared to ideal case will

Increase
Remain unaffected
Decrease
Other factors control it

## Compressors, Gas Turbines and Jet Engines In n₁ and n₂ are the indices of compression for the first and second stage of compression, then the ratio of work-done on the first and second stages (W₁/W₂) with perfect intercooling is given by

W₁/W₂ = n₂/n₁
W₁/W₂ = n₁(n₂ - 1)/n₂(n₁ - 1)
W₁/W₂ = n₁/n₂
W₁/W₂ = n₂(n₁ - 1)/n₁(n₂ - 1)

## Compressors, Gas Turbines and Jet Engines The ratio of the net work obtained from the gas turbine plant to the turbine work is known as

Pressure ratio
None of these
Work ratio
Compression ratio

## Compressors, Gas Turbines and Jet Engines Water gas is produced by

Passing air and a large amount of steam over waste coal at about 65°C
Partial combustion of coal, eke, anthracite coal or charcoal in a mixed air steam blast
Passing steam over incandescent coke
Carbonisation of coal

## Compressors, Gas Turbines and Jet Engines The pressure ratio in gas turbines is of the order of

0.16736111111111
0.084027777777778
2.5423611111111
0.37569444444444