A short chain is usually attached to the back of a petrol tanker and trailing behind it so that the
- petrol tanker is balanced on the road
- heat generated by friction in the engine can be conducted to the earth
-
charges generated by friction in the tanker are conducted to the earth
- tanker can move slowly as the chain touches the road surface
- chain can produce sound in resonance with the noise from the tanker‘s engine
The correct answer is: C
Explanation
Big vehicles gets charged because of friction between them and the air rushing past them.This is the reason tankers often have a metal chain dragging along the ground so that charge produced leaks to the ground through chain.