Read the passage and answer the question.
Conductors contain mobile charge carriers. In metallic conductors, these charge carriers are electrons. In a metal, the outer (valence) electrons part away from their atoms and are free to move. These electrons are free within the metal but not free to leave the metal. The free electrons form a kind of ‘gas’; they collide with each other and with the ions, and move randomly in different directions. In an external electric field, they drift against the direction of the field. The positive ions made up of the nuclei and the bound electrons remain held in their fixed positions.
Why is a person sitting inside a car safe during lightning?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → The electric field inside the cavity of a conductor is zero.
The metal body of a car is a closed conductor, and the people sit in the space inside it. This space is a cavity of the conductor. Whatever the charges and fields outside, the field inside such a cavity stays zero. This is called electrostatic shielding.
Option (1) Metals do not conduct electricity. — Incorrect. Metals are good conductors. As the passage says, they have free electrons that can move inside the metal.
Option (2) The car body is an insulator. — Incorrect. The body of a car is made of metal, which is a conductor. The protection comes from this conducting shell.
Option (3) The electric field inside the cavity of a conductor is zero. — Correct. The charge from the lightning stays on the outer surface of the metal body. The field inside the car stays zero, so the people inside are safe.
NCERT (2026-27):
Electrostatics of Conductors – “… Whatever be the charge and field configuration outside, any cavity in a conductor remains shielded from outside electric influence: the field inside the cavity is always zero. This is known as electrostatic shielding. …”