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