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