Ncert – class 8- science – Chapter 12: Some Natural Phenomena 2 Welcome to your Ncert - class 8- science - Chapter 12: Some Natural Phenomena 2 1. Lightning is a more common phenomenon during rainy season because of: high humidity high atmospheric density solar electrostatic disturbances moderate temperature None 2. Rub a glass tumbler with wool. Bring an inflated charged balloon, rubbed with wool, near refill. Then the balloon will burst. no reaction will be observed. both balloon and tumbler attract each other. both balloon and tumbler will repel each other. None 3. The sparks caused due to friction between two machine parts are: not similar to lightning none of the above similar to lighting lightning on a very small scale None 4. A lightning conductor consists of a conductor fixed on top of the building. a metal plate buried deep inside the ground connected to the ground end of copper strip. all of the above several sharp metal spiked connected to a thick copper strip. None 5. Suppose you are in a car and it is raining heavily with thunderstorms. Then what is the best way to protect yourself from a possible lightning strike? Run to a nearby tree Get out and stand under an electric pole Get out of the car and take cover under the car Remain in the car None 6. __________ is engineered to protect an elevated structure in the event of lightning strike. Copper wire A lightning conductor All of the above A lightening shield None 7. Other than lightning conductor, what are the objects which indirectly protect building from lightning / thunderstorm? All of the above. Water pipe in the building. Metal column used during construction. Electrical wires in the building. None 8. Which of the following one must do when caught in a Thunderstorm? Take shelter inside an isolated tree Take shelter in a safe place like car or bus Sit near a window Take shelter under an umbrella with a metallic end None 9. Why are lightning conductors pointed in shape? It allows more current. It repels the incident lightning discharge. To reduce mass. It attracts more electric charge due to very small radius and hence small surface area. None 10. What happens when you touch the water pipeline in the building during a thunderstorm? Your body provides earthing Your body will conduct electricity All of the above Charges will pass through your body None 11. Clouds get electrically charged when : The UV rays of sun falls on them Both Air molecules rub against water molecules and Cold currents of air rub against hot currents of air Air molecules rub against water molecules Cold currents of air rub against hot currents of air None 12. Explore and answer : Some children are playing in the playground. Suddenly clouds gather in the sky and there is thunder and lightning. What should they do now? The children should_______. Choose the correct answer. Just stand at their places Squat down Stand under a tree Run to their houses None 13. Why shouldn't one stand under a tree or a tall building during a thunderstorm? Lightning can strike trees and buildings, Trees and buildings may fall causing damage, None of the above, Trees and buildings do not offer enough escape ground, None 14. What kind of material should be used in an earthquake prone area? heavy weight light weight any of the above conducting material None 15. The lightning conductor used in building, protects the building by: Conducting the lightning safely to the ground Dissipating the electric charge away from the building None of these Absorbing the electric charge None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to comment Enter your email address to comment Enter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
