Question

When we touch a negatively charged conducting ball, we can see our hair strands to stand erect. Which of the following is the reason for this?

• A. Hair acquires charge form the ball and repel each other.
• B. Hair gets ionised with negative charge at its tip.
• C. Charges are spread in the air by the conducting ball.
• D. Hair gets ionized with negative chargeat its root.

Answer 1

The correct option is A Hair acquires charge form the ball and repel each other.

When you touch the ball, the charge accumulated on the ball flows through your body. As the negative charge flows through the skin, they reach the hair as well. This charges would stay on the body as long as it is not discharged into a charge sink like Earth. Since like charges repel and hair strands are light, they stand erect in order to maintain maximum distance with each other.