4) Supercharging is the process of

supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere

providing forced cooling air

injecting excess fuel for raising more load

supplying compressed air to remove combustion products fully

Answer is:

supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere

yes

to some extent

unpredictable

Answer is:

net efficiency

efficiency ratio

relative efficiency

overall efficiency

Answer is:

the ratio of volumes of air in cylinder before compression stroke and after compression stroke

volume displaced by piston per stroke and clearance volume in cylinder

ratio of pressure after compression and before compression

swept volume/cylinder volume

Answer is:

same

less

more or less depending on power rating

Answer is: