NCERT Solutions For Class 8 Science Chapter 12 Some Natural Phenomena SAQs

NCERT Solutions For Class 8 Science Chapter 12 Some Natural Phenomena Short Answer Questions

Question 1. If scientists know so much about earthquakes, can they also predict when and where the next one will strike?
Answer: No, it is not yet possible to predict when and where the next earthquake might occur because they cause disturbance in the Earth’s crust.

NCERT Solutions for Some Natural Phenomena SAQs Class 8

Question 2. Which of the following cannot be charged easily by friction?

1. A plastic scale
2. A copper rod
3. An inflated balloon
4. A woollen cloth

Answer: 2. As copper is a conductor, when rubbing it, the charges start flowing across the length of the copper rod, which constitutes an electric current. So, copper cannot be charged easily by friction.

Question 3. When a glass rod is rubbed with a piece of silk cloth, the rod

1. And the cloth both acquire a positive charge
2. Becomes positively charged, while the cloth has a negative charge
3. And the cloth both acquires a negative charge
4. Becomes negatively charged, while the cloth has a positive charge

Answer: 2. Becomes positively charged, while the cloth has a negative charge.

NCERT Solutions for Class 8 Science Some Natural Phenomena SAQs

Question 4. Write True and F against False against the Statements

1. Like charges attract each other.
2. A charged glass rod attracts a charged plastic straw.
3. The lightning conductor cannot protect a building from lightning.
4. Earthquakes can be predicted in advance.

Answer:

1. F, as like charges repel each other and unlike charges attract each other.
2. T, but it may also repel if charges are similar.
3. F, as a lightning conductor, can protect a building from lightning.
4. F, as it is not possible to predict the occurrence of earthquakes.

Question 5. Sometimes, a crackling sound is heard while taking off a sweater during winter. Explain.
Answer: The crackling sound heard while taking off a sweater during winters is due to the rubbing of two objects, i.e. body and the wool. The rubbing of the static charges produces lightning or a spark in our clothes that produces a crackling sound. The electric charges produced by rubbing are called static charges.

NCERT Solutions for Some Natural Phenomena Chapter 12 SAQs

Question 6. Explain why a charged body loses its charge if we touch it with our hand.
Answer: When we touch a charged body, it loses its charge due to the process of earthing. As our body is a good conductor of electricity, and transfers the charge to the earth.

Question 7. 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?
Answer: Destructive energy of an earthquake is measured on the Richter scale. Yes, the earthquake will be recorded by a seismograph in the form of seismic waves. The earthquake measuring 3 on the Richter scale cannot cause much damage.

Some Natural Phenomena Class 8 NCERT SAQs

Question 8. Suggest three measures to protect ourselves from lightning.
Answer: Lightning is an electric spark on a huge scale, which is caused by the accumulation of charges in clouds.

1. Some Measures to protect ourselves from lightning are as follows
2. We should stay under a covered area or inside the room.
3. We should not take a bath during lightning.
4. We should not use the TV, phone, or computers during lightning.

Question 9. Explain why a charged balloon is repelled by another charged balloon, whereas an uncharged balloon is attracted by another charged balloon.
Answer: Since both balloons acquire the same charges when being charged upon rubbing. Thus, they repel each other. On the other hand, one charged and the other uncharged balloon attract each other.

This is due to the property of charges that unlike charges attract each other.

The uncharged balloon, having the opposite charge, is attracted by the other charged balloon.

Question 10. List three states in India where earthquakes are more likely to strike.
Answer: Some earthquake-prone states of India are as follows

1. Kashmir
2. Gujarat
3. Rajasthan

Some Natural Phenomena SAQs NCERT Solutions Class 8

Question 11. Suppose you are outside your home and an earthquake strikes. What precautions would you take to protect yourself?
Answer: The precautions are as follows

1. We should move to an open space where trees and buildings are not available.
2. If we are driving, we should not come out. We should slow down the vehicle and move slowly away from that area to a safe spot.

Question 12. The weather department has predicted that a thunderstorm is likely to occur on a certain day. Suppose you have to go out on that day. Would you carry an umbrella? Explain.
Answer: Carrying an umbrella is not advisable during a thunderstorm. The rod of the umbrella and its supporting wires are made up of metal. Thus, during a thunderstorm, the conducting objects should be avoide.