Question

Victims who have survived lightning strikes have reported feeling the hair on the back of their necks or arms stand up just prior to being struck. Which of the following statement(s) is/are true?

I The hair on your body is attracted by the electric field of the imminent bolt.
II The electric field of the imminent bolt induces an electric charge on your body.
III The hair indicates the direction of the electric field on your body.

Answer 1

The imminent bolt induces a surplus of like charges on the body just before striking, that results in hair standing. The hairs are just trying to get away from each other because like charges repel. So, standing on its end offers maximum displacement with respect to other hairs on the skin.

Also, the direction of the electric field due to the induced charges on body is perpendicular to the skin, hence, the standing hairs directs towards the electric field produced on the body.

Hence, correct statements are :

(II) The electric field of the imminent bolt induces an electric charge on the body.

(III) The hair indicates the direction of the electric field on the body.