10:1

15:1

20:1

60:1

2-stroke engine

4-stroke petrol engine

4-stroke diesef engine

gas turbine.

varies as square root of the speed

Varies linearly to the speed

varies as square of the speed

varies as cube of the speed

increase first at fast rate and then slow

increase first at slow rate and then fast

decrease continuously

first increase, reach maximum and then decrease

in two phases

in three phases

in a single phase

in the form of air and water mixture