Automobile Engineering in ME
The main function of the tread pattern on tyre is that

The tread pattern protects the tyre's inner carcass from small stones and pieces of glass
In wet conditions, the tread grooves expel water that is drawn between the tyre and road surface
The crests between the tread grooves absorb road noise
The tread grooves pass air between the tyre and road surface, thereby preventing tyre from overheating

ANSWER DOWNLOAD EXAMIANS APP

Automobile Engineering in ME
The compression ratio in petrol engine is kept less than in Diesel engine because

It is just customary to have less compression ratio in petrol engines
Less compression ratio gives better performance
Higher or equivalent compression ratio in petrol engines is not possible due to pre-ignition
It makes petrol engines lighter

ANSWER DOWNLOAD EXAMIANS APP

Automobile Engineering in ME
The main feature of Macpherson strut suspension is that

Non vertical external forces are supported by the suspension arms
The unsprung mass in lighter
The assembly is slightly more complicated in design
The vertical size of the suspension can be made more compact

ANSWER DOWNLOAD EXAMIANS APP