Question

When a plastic refill is rubbed with polythene, which object acquires an electric charge?

Answer 1

Electric charge:

1. Electric charge is a basic feature of matter that can never be found devoid of charge. Positive and negative charges are the two types of electric charges.
2. If a body has an excess of electrons, it is said to be negatively ($-$) charged and if it is deficient, it is said to be positively ($+$) charged.

A body or an entity can be charged in three ways:

1. Friction
2. Contact
3. Electrostatic induction

Charging by friction:

1. Frictional electricity is the electricity created as a result of friction.
2. Whenever we rub two neutral things together, electrons will be transferred from one to the other attributable to structural changes caused by frictional forces. In this procedure, one of the bodies receives a negative charge, whereas the other receives a positive charge of equivalent size.

Example of charging by friction:

1. Whenever a plastic refill is brushed against polythene, both the plastic refill and the polythene become charged. Charges that are similar repel each other, whereas charges that are dissimilar attract each other.
2. Whenever a glass rod is brushed with silk fabric, the glass gains a positive charge while the silk cloth gains a negative charge. Electrons are extracted from the glass rod and deposited on silk fabric.

Therefore, whenever a plastic refill is rubbed with polythene, both the plastic refill and the polythene become charged. The friction charging technique is used here.