# NCERT Solutions for Class 8 Science Science - NCERT Solution Chapter 15

## Some Natural Phenomena Class 8

### Exercise : Solutions of Questions on Page Number : 197

Q1 :

Which of the following cannot be charged easily by friction?

(a) A plastic scale

(b) A copper rod

(c) An inflated balloon

(d) A woollen cloth

(b) A copper rod

Only non-conducting materials can be easily charged by friction. Copper is a highly conducting materials. Therefore, a copper rod cannot be charged easily by friction.

Q2 :

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.

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

When an object is charged by rubbing it against another object, the two objects get oppositely charged. By convention, it is considered that the charged acquired by the glass rod is positive and charged acquired by the cloth is negative. Therefore, the rod becomes positively charged and the cloth becomes negatively charged.

Q3 :

Write T against true and F against false in the following statements.

(a) Like charges attract each other. (T / F)

(b) A charged glass rod attracts a charged plastic straw. (T / F)

(c) Lightning conductor cannot protect a building from lightning. (T/F)

(d) Earthquakes can be predicted in advance. (T / F)

Q4 :

Sometimes, a crackling sound is heard while taking off a sweater during winters. Explain.

Q5 :

Explain why a charged body loses its charge if we touch it with our hand.

Q6 :

Name the scale on which the destructive energy of an earthquake is measured. An earthquake measures 3 on this scale. Would it be recorded by a seismograph? Is it likely to cause much damage?

Q7 :

Suggest three measures to protect ourselves from lightning.

Q8 :

Explain why a charged balloon is repelled by another charged balloon whereas an uncharged balloon is attracted by another charged balloon?

Q9 :

Describe with the help of a diagram an instrument which can be used to detect a charged body.

Q10 :

List three states in India where earthquakes are more likely to strike.

Q11 :

Suppose you are outside your home and an earthquake strikes. What precaution would you take to protect yourself?