In this chapter, we will study two natural phenomena

  • Lightning
  • Earthquake


To learn about Lightning, we should first know what an electric charge is

What is Charge

It is the amount of electricity contained in an object

There are 2 types of charges

  1. Positive Charge
  2. Negative Charge


How is charge obtained?

It is obtained by friction caused by rubbing of 2 objects.

What are Different Rules of Charge?

There are two rules of charges

  • Like Charges Repel Each other
  • Unlike Charges Attract Each other



Like Charges Repel Each other

It means that if we bring 2 objects which have the same charge (both positive or both negative) together, they repel each other.


Suppose we rub 2 balloon against wall, they become negatively charged.

If we bring both of them together, they repel each other


Similarly, if we bring 2 objects which are positively charged together

they repel each other



Unlike Charges Attract each other.

It means that if we bring 2 objects, one Positively Charged and one Negatively Charged together,

they attract each other



Suppose we rub a glass rod with silk, it becomes positively charged.

Similarly, if we rub a balloon against the wall ,it becomes negatively charged

Now, if we bring this charged glass rod with charged plastic straw, both attract as one is positively charged and other negatively charged



Movement of Electric Charges

Static Charge

Charge which does not move by themselves is called static charge

Charge which is generated by rubbing is static charge

Electric Current

When charge moves, it constitutes Electric Current


Current which make bulb glow. 

Current which make wire heat




NCERT Question 8 - Explain why a charged balloon is repelled by another charged balloon whereas an uncharged balloon is attracted by another charged balloon?

View Answer


NCERT Question 2 - When a glass rod is rubbed with a piece of silk cloth the rod

(a) and the cloth both acquire positive charge.

(b) becomes positively charged while the cloth has a negative charge.

(c) and the cloth both acquire negative charge.

(d) becomes negatively charged while the cloth has a positive charge

View Answer


NCERT Question 3 (b) - Write T against true and F against false in the following statements:

A charged glass rod attract a charged plastic straw (T/F)

View Answer


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Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo