Question

A charged insulator can be discharged by passing it just above a flame. This is because the flame

• A. warms it
• B. dries it
• C. contains carbon dioxide
• D. contains ions

Answer 1

The correct option is D contains ions

A flame consists of a cloud of hot ions, the overall charge is neutral but there are many ions of both $+$ and $-$ charge.

This mixture of $+$ and $-$ ions means that if any charged surface is introduced into the flame of gases, it will find whatever charges it needs to be neutralized. Hence, a charged insulator can be completely discharged by passing it through the warm air above a burning flame.