(a) Name two methods of electrostatic charging.
A polythene strip may be charged by rubbing with a soft cloth. Before rubbing the polythene strip with a soft cloth, both the strip and the cloth are neutral. After rubbing, the polythene strip is charged negatively.
(b) Does a neutral body possess any charges? Explain.
(c) Is the soft cloth charged after rubbing? If it is, is it charged positively or negatively?
(d) What happens when the polythene strip is rubbed with the soft cloth?
*************************
Answer:
(a) Friction and induction
(b) Yes. There are both positive and negative charges, but it is neutral because the total number of positive charges is equal to the total number of negative charges.
(c) Yes. It is positively charged.
(d) Friction between the 2 materials pull electrons from the cloth to the polythene strip. The polythene strip will possess extra negative charges and becomes negatively charged, whereas the soft cloth loses negative charges and therefore becomes positively charged.