Question

Why is a car or a bus a safe place during lightning?
A. Because it does not rain inside the bus.
B. Because lightning cannot travel through the glass.
C. Because a car or a bus is insulated from the Earth.
D. None of the above.

Answer 1

Hint: A bus or a car has a metal surface in its exterior layer, and metals are a good conductor of electricity. Thus, a metal surface can act as a medium to transfer current (i.e., the lightning) from the surrounding directly to the ground, without affecting the person inside it, so he remains safe.

Complete answer:
At high altitude due to friction with air the clouds get charged. This charged cloud induces an opposite type of charge to anything which is close to it or to anything made up from metal. If the amount of induced charge is high enough this may start attracting the charges of the cloud towards itself (as opposite charges attract each other). If the attraction was successful then all the charges from the cloud moves to the object which had induced charge on itself thus a lightning occurs and we see white spark.

A car or a bus is generally made up of a metal on its outer surface and with insulators in its inner surfaces. If the charges induced by the cloud on the metal surface of the bus is high enough it can attract the charges which are present in the cloud towards itself thus a lightning can occur on the outer surface of the bus or car due to the tremendous amount of charge transfer from cloud to the metal.

Frame of a bus or car being made from metal (good conductor of electricity) would direct the current around the objects and discharge it safely to the ground while shielding the objects inside it. Even the insulation inside the bus also prevents it from being damaged by not allowing the charges to pass through it.

So, the option C is correct.

Note: The charge carried by the cloud is static electric charges caused by rubbing and transfer of electrons from one body to another body. Induction is the process through which a charge body induces an opposite charge in a body close to it. Sometimes due to this induction (when the weather is windy or rough) we might get a shock if we touch the metal surface of the bus or car.