Some Natural Phenomena class 8 questions and answers: Science Class 8 chapter 12 question answer
| Textbook | Ncert |
| Class | Class 8 |
| Subject | Science |
| Chapter | Chapter 12 |
| Chapter Name | Some Natural Phenomena ncert solutions |
| Category | Ncert Solutions |
| Medium | English |
Are you looking for Class 8 Science chapter 12 question answer? Now you can download ncert solutions for class 8 science chapter 12 pdf from here.
Question 1: Select the correct option in Questions 1 and 2.
Which of the following cannot be changed easily by friction?
(a) A plastic scale
(b) A copper rod
(c) An inflated balloon
(d) A woollen cloth
Answer 1: (b) A copper rod
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.
Answer 2: (b) becomes positively charged while the cloth has a negative charge.
Question 3: 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 attract 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)
Answer 3: (a) False
(b) True
(c) False
(d) False
Question 4: Sometimes, a crackling sound is heard while taking off a sweater during winters. Explain.
Answer 4: The electric discharge takes place between the body and the sweater due to friction. At the time of electric discharge some energy is released. In this case energy is released in the form of crackling sound.
Question 5: Explain why a charged body loses its charge if we touch it with our hand.
Answer 5: The charges get conducted to the earth through our body when we touch it, and the conductor loses its charge. This phenomenon is known as electric discharge.
Question 6: 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 6: The Richter scale is used to determine how destructive an earthquake is. The scale ranges from one to ten. A seismograph would record a reading of magnitude 3 on the Richter scale. If the earthquake has a magnitude of 3 on the Richter scale, it is unlikely to cause significant damage. Earthquakes of a magnitude greater than 5 are generally considered destructive in nature.
Question 7: Suggest three measures to protect ourselves from lightning.
Answer 7: are several strategies to shield ourselves against lightning.
- (i) Stay in a confined space at all times. If you’re in a car, keep the windows closed and stay there until the lightning passes.
- (ii) Avoid coming into contact with any electrical, phone, or metal pipes.
- (iii) You should never take a bath in running water since this could shock you.
Question 8: Explain why a charged balloon is repelled by another charged balloon whereas an uncharged balloon is attracted by another charged balloon?
Answer 8: A charged balloon is repelled by another charged balloon because both carry same charges and we know same charges repel each other whereas an uncharged balloon is attracted by charged balloon because unlike charges attract each other.
Question 9: Describe with the help of a diagram an instrument which can be used to detect a charged body.
Answer 9: An electroscope can be used to detect if a body is charged or not. When a charged body touches the metal conductor, the metal strips repel each other and open wide. This proves that the body is charged.
Question 10: List three states in India where earthquakes are more likely to strike.
Answer 10: India is prone to earthquakes, especially in regions located along tectonic plate boundaries. Three states where earthquakes are more likely to strike are Jammu and Kashmir, Uttarakhand, and Sikkim.
Question 11: Suppose you are outside your home and an earthquake strikes. What precaution would you take to protect yourself?
Answer 11: If an earthquake strikes while I’m outside my home, I would follow these precautions to protect myself:
- Stay away from buildings: I would move away from any structures, such as houses, shops, or electrical poles, to avoid the risk of falling debris.
- Seek open space: I would find an open area, such as a park or empty lot, to avoid being near objects that could collapse or cause injury.
- Avoid underpasses or overpasses: I would stay clear of bridges, tunnels, and overpasses since they are more vulnerable to damage during earthquakes.
- Drop to the ground: If I can’t find an open area quickly, I would drop to my knees, cover my head, and protect myself from falling debris until the shaking stops.
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 12: No, it’s not advisable to use an umbrella when it’s thunder storming. Lightning is present during the thunderstorm, and the charges from the cloud may transfer to the umbrella’s metal rod, shocking the person holding it. Thus, it is not advisable to use an umbrella when lightning is present.