A short chain is usual attached to the back of a petrol tanker trailing behind it to ensure that the
Answer Details
The correct option is: charges generated by friction in the tanker can be conducted to the earth.
The short chain is usually made of metal and is attached to the back of a petrol tanker trailing behind it to prevent the buildup of static electricity caused by friction between the tanker and the road surface. As the tanker moves, friction between the wheels and the road generates static electricity, which can accumulate on the metal body of the tanker. If the static charge buildup is not dissipated, it can cause a spark, which can ignite the fuel vapor, leading to an explosion. The short chain attached to the tanker helps to conduct the static charge to the earth, reducing the risk of explosion.