Automobile Engineering in ME
The power source for a brake booster is

Exhaust manifold pressure
Hydraulic pump
The pressure difference between the atmospheric pressure and the vacuum pressure in the intake manifold
Electricity

ANSWER DOWNLOAD EXAMIANS APP

Automobile Engineering in ME
In a ventilated disc brake

Disc contains radial vanes between its rubbing surfaces for optimum cooling performance
A duct directs air towards the caliper for cooling while the vehicle is moving
Disc contains many small holes for optimum cooling performance
Caliper is covered with cooling fins

ANSWER DOWNLOAD EXAMIANS APP