Ncert – class 9- science – Chapter 10 – Work and Energy 2 Welcome to your Ncert – class 9- science – Chapter 10 – Work and Energy 2 1. The gravitational potential energy of an object is due to its mass its acceleration due to gravity its height above the earthï½s surface all of the above. None 2. A ball is dropped from a height of 10 m. Its potential energy increases and kinetic energy decreases during the falls Its potential energy is equal to the kinetic energy during the fall. The potential energy decreases and the kinetic energy increases during the fall. The potential energy is �0� and kinetic energy is maximum while it is falling. None 3. A students caries a bag weighing 5 kg from the ground floor to his class on the first floor that is 2 m high. The work done by the boy is 1 J 10J 100J 1000J None 4. Moon revolves around the earth due to gravitational force (F) of earth on moon. The work done by the gravitational force is (r = radius of circular orbit of moon) F. 2 π r F. π r zero negative work None 5. A load of 50 kg is pulled upward by 5 m. The work done by the external force is (g = 10 m/s2) 250 J 2500 J - 250 J - 2500 J None 6. A body is moved through a distance of 3 m in the following different ways. In which case is the maximum work done? when pushed over an inclined plane when lifted vertically upward when pushed over smooth rollers when pushed on a plain horizontal surface None 7. Two bodies of equal weight are kept at heights of h and 1.5h, respectively. The ratio of their PE is 3 : 2 3:3 2:3 1:1 None 8. In the SI system, the unit of potential energy is newton joule watt metre per second None 9. The practical unit for the measurement of electric power is: watt kilowatt kilowatt hour horse power None 10. Which of the following will lead to a change in kinetic energy of a body? change in its mass change in its velocity all of the above none of the above None 11. What is potential energy? Energy of an object due to its position or arrangement in a system Energy of an object due to its nature or arrangement in a system Energy of an object due to its shape or arrangement in a system None None 12. What is kinetic energy? Energy possessed by a body by the virtue of its motion Energy possessed by a body by the virtue of its shape Energy possessed by a body by the virtue of its size None None 13. Work is said to be done when: (i) a force should act on an object, and (ii) the object must be displaced. (i) no force should act on an object, and (ii) the object must be displaced. (i) a force should act on an object, and (ii) the object must not be displaced. (i) no force should act on an object, and (ii) the object must not be displaced. None 14. The expression for work done, when the displacement is in the direction of the force is: F×S - F /S (F×S)/2 0 None 15. Energy can be defined as: The capacity to do work Work done in unit time A push or a pull Attraction between two oppositely charged particles 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.
