Class IX Chapter : Force and Laws of Motion Date of Taking Test : December 25, 2024 Time: 20 Minutes 1. Two forces X and Y are acting on a block kept on a table. Which of the following conditions is necessary for X and Y to be considered as balanced forces? (a) Magnitude of X = Magnitude of Y and direction of X = direction of Y (b) Magnitude of X = Magnitude of Y and direction of X is opposite to direction of Y (c) Magnitude of X < Magnitude of Y and direction of X = direction of Y (d) (a) Magnitude of X > Magnitude of Y and direction of X = direction of Y None 2. Observe the figure carefully and answer the following question (a) < 25 N (b) = 25 N (c) > 25 N (d) ≥ 25 N None 3. Galileo performed the famous experiment shown in the diagram. (a) Objects move with a constant speed when no force acts on them. (b) When a marble rolls down an inclined plane, its velocity increases (c) The velocity of marble increases when it climbs up (d) The marble falls under the unbalanced force of gravity. None 4. When we are standing in a bus and the bus begins to move forward suddenly, we tend to _________ (a) fall down. (b) remain stationary (c) fall forwards (d) fall backwards None 5. Which of the following is NOT true for momentum. (a) Momentum has both direction and magnitude. (b) The SI unit of momentum is kilogram-metre second (kg ms) (c) The direction of momentum is the same as that of velocity, v (d) The momentum, p of an object is defined as the product of its mass, m and velocity, v. None 6. A force also produces change in __________ (a) energy (b) density (c) mass (d) momentum None 7. Identify the relation which correctly depicts the second law of motion mathematically (a) The rate of change of momentum ∝ Change in applied force (b) The rate of change of momentum ∝ Change in velocity (c) The rate of change of momentum ∝ Change in mass (d) The rate of change of momentum ∝ 1/Change in applied force momentum None 8. Which of the following statements is NOT true for third law of motion? (a) When one object exerts a force on another object, the second object instantaneously exerts a force back on the first. (b) These two forces are always equal in magnitude but opposite in direction. (c) These two forces are always equal in magnitude and act upon the same object (d) These forces act on different objects and never on the same object. None 9. A passenger in a moving bus throws a ball in the upwards direction and the ball falls behind him. This shows that the motion of bus is ___________ motion. (a) uniform (b) accelerated (c) retarded (d) uniform circular None 10. Dust particles start coming off when a hanging carpet is beaten with a stick. Which of the following explains this? (a) Newton’s third law of motion (b) Newton’s law of gravitation (c) Newton’s first law of motion (d) Newton’s second law of motion None 11. A ball of mass 0.2 kg is sliding on a frictional horizontal table with a constant velocity of 4mm/s. The amount of force required to keep the ball moving with the same velocity is ___________ (a) 0 N (b) 0.8 N (c) 2 N (d) 8 N None 12. It is easier to accelerate a small car as compared to a big car. The unit of the quantity responsible for this is ___________ (a) m/s (b) kg.m/s (c) Kg (d) m/s2 None 13. A body of mass 20 kg is accelerating at a rate of 0.25m/s2. The force acting on the body is ________. (a) 5 N (b) 10 N (c) 20 N (d) 50 N None 14. A fielder in cricket match while catching a fast moving ball pulls his hands backwards. Because this enables him: (a) to exert larger force on the ball (b) reduces the impact of the ball (c) to balance the rate of change of momentum (d) increases the rate of change of momentum None 15. If the mass of a body is doubled and its velocity becomes half, then the linear momentum of the body will (a) remain same (b) become double (c) become half (d) become four times. None 16. Assertion (A): An object at rest remains at rest or in uniform motion in a straight line unless compelled to change that state by an applied force. Reason (R): Inertia is an inherent tendency of a body to resist any change in its state (a) Both A and R are true and R is the correct explanation of A (b) Both A and R are true and R is NOT the correct explanation of A (c) A is true but R is false (d) A is false but R is true None 17. Assertion (A): Momentum is a vector quantity. Reason (R): Momentum is the product of mass and velocity. (a) Both A and R are true and R is the correct explanation of A (b) Both A and R are true and R is NOT the correct explanation of A (c) A is true but R is false (d) A is false but R is true None 18. Assertion (A): Newton’s second law gives quantitative definition of force. Reason (R): Newton’s second law of motion states that the rate of change of momentum of an object is inversely proportional to the applied unbalanced force in the direction of force. (a) Both A and R are true and R is the correct explanation of A (b) Both A and R are true and R is NOT the correct explanation of A (c) A is true but R is false (d) A is false but R is true None 19. Assertion (A): Forces always occur in pairs. Reason (R): According to Newton’s first law of motion, action and reaction forces are equal and opposite. (a) Both A and R are true and R is the correct explanation of A (b) Both A and R are true and R is NOT the correct explanation of A (c) A is true but R is false (d) A is false but R is true None 20. Assertion (A): Recoil of a gun can be explained by the Newton’s first law of motion Reason (R): According to Newton’s third law of motion, forces always occur in pairs. (a) Both A and R are true and R is the correct explanation of A (b) Both A and R are true and R is NOT the correct explanation of A (c) A is true but R is false (d) A is false but R is true None 1 out of 1 Leave a Reply Cancel replyYour email address will not be published. Required fields are marked *Name * Email * Website Comment * Save my name, email, and website in this browser for the next time I comment.