Question

Explore and answer :

Petrol tankers plying on highways often have metal chains attached to that drag along the road. Could you say why ?

Answer 1

Given that petrol tankers plying on highways often have metal chains attached to them. We have to find reason for this.
The reason is that the movement of vehicle on road produces electric charges and hence sparkling due to rubbing of tyres on road which is very dangerous since petrol is very inflammable. So, metal chains that drag along the road helps in absorbing these dangerous electric charges produced by the vehicle's tyres.