Ncert – class 9- science – Chapter 8 – Force and Laws of Motion 2 Welcome to your Ncert – class 9- science – Chapter 8 – Force and Laws of Motion 2 1. Which one is correct if a bullet is fired from a rifle? There is no motion of bullet and rifle. Rifle moves in the backward direction and bullet moves in the forward direction. Bullet moves in the backward direction and rifle moves in the forward direction. Bullet and rifle both move in the backward direction. None 2. An Object moving along a straight path with an accelerated motion. The correct statement about the object-A Its velocity keeps changingB Its speed keeps changingC A force is always acting on itD Its mass keeps on changing All of these (a), (b) and (c) are correct (b) and (c) are correct (a) and (b) are correct None 3. Identify the incorrect statement. The tension of a string always pulls a body. The spring force always pushes a body. Frictional force always acts parallel to the surface of contact. The weight of a body always acts towards the centre of the Earth. None 4. Statement A: Gravitational force is the weakest force in nature.Statement B: Electrostatic force is an example of non – contact forces.Which of the above two statements is true? Statement A is true Neither statement A nor B are true Statement B is true Both the statement a and b are true. None 5. Match the following with correct response.(1) Action and reaction(2) Magnitude of force(3) Momentum(4) Resultant of balanced force (A) No acceleration(B) Newton’s second law(C) Act on different objects(D) Vector quantity 1-B, 2-D, 3-A, 4-C 1-D, 2-A, 3-C, 4-B 1-C, 2-B, 3-D, 4-A 1-A, 2-C, 3-B, 4-D None 6. If an object moves with a uniform velocity we can conclude that it has uniform acceleration no unbalanced force acts on it there is no force acting on the body an unbalanced force acts on the body None 7. Which of the following is true about action and reaction forces acting on two bodies of equal masses? Action and reaction forces are equal and opposite and produce equal and opposite acceleration. Action and reaction forces are equal and opposite and produce unequal and opposite acceleration. Action and reaction forces are unequal and opposite and produce equal and opposite acceleration. Action and reaction forces are unequal and opposite and produce unequal and opposite acceleration. None 8. Find the time for which a force of 1kgwt acts on a body of mass 1 kg moving with a uniform speed of 4m/s to stop the body. 0.2 s 0.8 s 0.4 s 0.6 s None 9. When a force is exerted on an object, it can change its-A StateB PositionC ShapeD Direction (b) and (c) are correct (a) and (b) are correct (a), (b) and (c) are correct All of these None 10. A carpenter exerts a force of magnitude 1.5 N at right angles on the surface of a nail of mass 3 gram to drive it into a wooden plank. If the plank offers a resistive force of 0.6 N and the time of interaction of hammer and the nail 0.01 s, the depth through which the nail penetrates is 15m 1.5 mm 1.5 cm 15 cm None 11. Match the following with correct response.(1) Cause of acceleration(2) Quantitative measure of inertia(3) powder applied on carom board(4) Tyres of vehicles made Rough (A) Mass(B) Increases friction(C) Decreases friction(D) Force 1-A, 2-C, 3-B, 4-D 1-B, 2-D, 3-A, 4-C 1-D, 2-A, 3-C, 4-B 1-C, 2-B, 3-D, 4-A None 12. The people in a bus are pushed backwards when the bus starts suddenly because of Inertia due to rest External force Inertia due to direction Inertia due to motion None 13. It is due to which of the following reasons that a scooter generally slips on an oily road? All the above. Friction between tyres and road increases. Friction between tyres and road remain same. Friction between tyres and road decreases. None 14. Two spring balances pull each other in opposite directions. If the reading of one spring balance is 2 N, the reading shown by the second spring balance will be 2.5 N 2 N 3.5 N 4 N None 15. A force of 10 N acts on a ball moving on a surface. The force of friction that must act between the surface of the ball and the surface so that the ball keeps on moving with constant velocity over the surface must be 20 N 10 N Zero 100 N 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.
