ICSE ICSE Class 8 - CISCE Question Bank Solutions

What are free electrons?

What causes the charging of two objects when they are rubbed together?

In each of the following cases, State which body loses electrons:
(a) A glass rod when rubbed with silk.
(b) An ebonite rod when rubbed with fur.

A glass rod is rubbed with silk. Explain the charging of the glass rod and the silk on the basis of electron movement.

An ebonite rod is rubbed with fur. Explain the charging of the ebonite rod and the fur on the basis of electron movement.

Distinguish between conductors and insulators of electricity.

Give one example each of a conductor and an insulator of electricity.

State two ways of charging a conductor.

Name the way of charging a conductor in which the charge is shared.

Describe the method of charging a conductor by conduction.

A metal rod A is to be charged positively by using another charged rod B. What should be the kind of charge on the rod B if charging is to be done by conduction?

Explain the charging by conduction in terms of movement of electrons.

Describe the method of charging a conductor by induction.

Explain the charging by induction in terms of movement of electrons.

Figure below shows a metal rod AB placed on an insulating stand.

In figure (a) a negatively charged ebonite rod C is touched with the metal rod AB, while in figure (b), the negatively charged ebonite rod C is held near the rod AB. State the kind of charges at the ends A and B of the rod, in each case.

Can you charge an insulator by the method of conduction?

What is an electroscope?

Describe a pith ball electroscope. how can you use it to test whether a body is charged or uncharged?

Name the two types of electroscopes.

How will you use a pith ball electroscope to find out whether the charge on a charged body is positive or negative?