Ncert – class 8- science – Chapter 12: Some Natural Phenomena 1 Welcome to your Ncert - class 8- science - Chapter 12: Some Natural Phenomena 1 1. Lightning is caused in the atmosphere primarily due to Discharge between one charged and one neutral cloud. Opposite charges accumulation at edges of a cloud. Discharge between two similarly charged clouds. None of these None 2. 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 3. What is a positive charge? The charge acquired by a glass rod when it is rubbed with silk 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 None 4. 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 5. Some object can be charged by _________ with other objects. Joining Rubbing Heating Touching None 6. Like charges repel and unlike charge Repel or attract Any thing may happen Repel each other Attract each other None 7. Why is Earthing done in buildings? To transfer extra current to air To protect us from electric shocks None of these To give extra strength to the building None 8. What is the cause for the streaks of bright light and sound produced during lightning? Meeting of negative charges Meeting of positive charges Meeting of unlike electric charges Meeting of like electric charges None 9. An ebonite rod is rubbed with fur. The charge on the ebonite rod is ______ and the charge on the fur is _______. Positive, Positive Negative, Positive Negative, Negative Positive, Negative None 10. How does charges separate during a thunderstorm? None of these Due to rubbing of air particles Due to movement of air Due to movement of air current and water droplets None 11. 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 one strip will move away while other will remain same. the plastic strips will come more closer. the plastic strips will not diverge None 12. What are the weak zones around the boundaries of plates underneath Earth, which are prone to slide and cause earthquakes? Sliding zone Fault zone Eruption zone Explosive zone None 13. The process of transferring a charge from a charged body to the earth is called Hydrolysis Electrolysis Earthing Discharging None 14. If the Richter scale reading for an earthquake is less than 3.5 then what can you say about the earthquake? Causes major damage to poorly constructed buildigs Often felt & rarely causes damage Major earth quake causes serious damage Generally not felt but recorded None 15. Building can be protected from lightening by using All of these Lightening rod on the levels of building Wooden logs at the top of building Lightening rod at the top of building None 16. During the thunderstorm, ________ move upwards while ________ move downards. Air currents, charges Air currents, water droplets Water droplets, charges Water droplets, air currents None 17. When a glass rod is rubbed with dry silk cloth, the charge acquired by the silk cloth is none of the above Negative Both positive and negative Positive None 18. Which of the following is not a natural phenomenon? Cyclone Earthquake Lightening Cooking None 19. 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? (ii) (i) (iv) (iii) None 20. Which of the following natural phenomenon is most destructive in terms of loss of life and property? winds Storms Earthquake Lightening 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.
