Ncert – class 8- science – Chapter 12: Some Natural Phenomena 1 Welcome to your Ncert - class 8- science - Chapter 12: Some Natural Phenomena 1 1. In an electroscope, if aluminium strips are replaced by plastic strips, and a charged object is touched with the metal top of the electroscope: the plastic strips will come more closer. the plastic strips will not diverge the plastic strips will diverge one strip will move away while other will remain same. None 2. An ebonite rod is rubbed with fur. The charge on the ebonite rod is ______ and the charge on the fur is _______. Negative, Negative Positive, Negative Positive, Positive Negative, Positive None 3. Like charges repel and unlike charge Repel each other Any thing may happen Attract each other Repel or attract None 4. Why is Earthing done in buildings? None of these To transfer extra current to air To protect us from electric shocks To give extra strength to the building None 5. What is the cause for the streaks of bright light and sound produced during lightning? Meeting of like electric charges Meeting of unlike electric charges Meeting of positive charges Meeting of negative charges None 6. What are the weak zones around the boundaries of plates underneath Earth, which are prone to slide and cause earthquakes? Sliding zone Explosive zone Eruption zone Fault zone None 7. Lightning is caused in the atmosphere primarily due to None of these Discharge between two similarly charged clouds. Opposite charges accumulation at edges of a cloud. Discharge between one charged and one neutral cloud. None 8. Which of the following natural phenomenon is most destructive in terms of loss of life and property? winds Earthquake Storms Lightening None 9. How does charges separate during a thunderstorm? Due to movement of air None of these Due to rubbing of air particles Due to movement of air current and water droplets None 10. Two objects when rubbed together, get charged. The charges on them are: Unequal and similar Equal and opposite Unequal and opposite Equal and similar None 11. Building can be protected from lightening by using Wooden logs at the top of building All of these Lightening rod on the levels of building Lightening rod at the top of building None 12. During the thunderstorm, ________ move upwards while ________ move downards. Air currents, water droplets Water droplets, charges Air currents, charges Water droplets, air currents None 13. When a glass rod is rubbed with dry silk cloth, the charge acquired by the silk cloth is Both positive and negative Negative Positive none of the above None 14. Following are precautions one must take in case a storm is accompanied by lightning. i) Do not take shelter under a tree. ii) Do not take shelter under an umbrella with a metallic end. iii) Do not take shelter in open garages, storage sheds, etc. iv) Do not take shelter in a bus in the open. Which one of these is not correct? (i) (iv) (ii) (iii) None 15. If the Richter scale reading for an earthquake is less than 3.5 then what can you say about the earthquake? Major earth quake causes serious damage Often felt & rarely causes damage Causes major damage to poorly constructed buildigs Generally not felt but recorded None 16. Which of the following is not a natural phenomenon? Earthquake Cooking Cyclone Lightening None 17. The process of transferring a charge from a charged body to the earth is called Electrolysis Hydrolysis Earthing Discharging None 18. Some object can be charged by _________ with other objects. Touching Rubbing Heating Joining None 19. What happens when two bodies are rubbed together None They get equal charged but the same nature They get equal charged but the opposite nature Nothing happend with rubbing None 20. What is a positive charge? The charge acquired by plastic straw when it is rubbed with a silk None of these The charge acquired by silk when it is rubbed with a glass rod The charge acquired by a glass rod when it is rubbed with silk 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 commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
