Practice Questions

Q4. A thin circular disc of mass M and radius R is rotating in a horizontal plane about an axis passing through its centre and perpendicular to its plane with angular velocity ω. If another disc of same dimensions but of mass M/2 is placed gently on the first disc co-axially, then the new angular velocity of the system is : (1) 3 ω (2) 5 ω 2 4 (3) 2 ω (4) 4 ω 3 5

Q4. A block of mass 100 kg slides over a distance of 10 m on a horizontal surface. If the co-efficient of friction between the surfaces is 0. 4 , then the work done against friction (in J) is: (1) 4200 (2) 3900 (3) 4000 (4) 4500

Q4. A heavy box of mass 50 kg is moving on a horizontal surface. If co-efficient of kinetic friction between the box and horizontal surface is 0.3 then force of kinetic friction is : (1) 1.47 N (2) 147 N (3) 14.7 N (4) 1470 N

Q5. The excess pressure inside a soap bubble is thrice the excess pressure inside a second soap bubble. The ratio between the volume of the first and the second bubble is: (1) 1 : 9 (2) 1 : 3 (3) 1 : 27 (4) 1 : 81

Q5. A bullet of mass 50 g is fired with a speed 100 m/s on a plywood and emerges with 40 m/s. The percentage loss of kinetic energy is : (1) 84% (2) 16% (3) 32% (4) 44%

Q5. A body of mass 1000 kg is moving horizontally with a velocity 6 m s−1 . If 200 kg extra mass is added, the final velocity (in m s−1 ) is: (1) 6 (2) 2 (3) 3 (4) 5

Q5. Three bodies A, B and C have equal kinetic energies and their masses are 400 g. 1.2 kg and 1.6 kg respectively. The ratio of their linear momenta is : (1) √2; √3; 1 (2) 1 : √3 : 2 (3) 1 : √3 : √2 (4) √3 : √2 : 1

Q5. A body of mass 50 kg is lifted to a height of 20 m from the ground in the two different ways as shown in the figures. The ratio of work done against the gravity in both the respective cases, will be : (1) 1 : 2 (2) √3 : 2 (3) 2 : 1 (4) 1 : 1

Q6. Four particles A, B, C, D of mass m2 , m, 2m, 4m, have same momentum, respectively. The particle with maximum kinetic energy is : (1) B (2) A (3) D (4) C

Q6. A planet takes 200 days to complete one revolution around the Sun. If the distance of the planet from Sun is reduced to one fourth of the original distance, how many days will it take to complete one revolution? (1) 25 (2) 50 (3) 100 (4) 20 JEE Main 2024 (29 Jan Shift 2) JEE Main Previous Year Paper

Q6. Two satellite A and B go round a planet in circular orbits having radii 4R and R respectively. If the speed of A is 3v, the speed of B will be : (1) 3v (2) 6v (3) 4 v (4) 12v 3

Q6. Escape velocity of a body from earth is 11 . 2 km s-1. If the radius of a planet be one-third the radius of earth and mass be one-sixth that of earth, the escape velocity from the plate is: (1) 11 . 2 km s-1 (2) 8 . 4 km s-1 (3) 4 . 2 km s-1 (4) 7 . 9 km s-1

Q6. A player caught a cricket ball of mass 150 g moving at a speed of 20 m/s. If the catching process is completed in 0.1 s, the magnitude of force exerted by the ball on the hand of the player is: (1) 3 N (2) 300 N (3) 150 N (4) 30 N

Q6. Assuming the earth to be a sphere of uniform mass density, a body weighed 300 N on the surface of earth. How much it would weigh at R/4 depth under surface of earth ? (1) 75 N (2) 300 N (3) 375 N (4) 225 N

Q6. If a rubber ball falls from a height h and rebounds upto the height of h/2. The percentage loss of total energy of the initial system as well as velocity ball before it strikes the ground, respectively, are : (1) 50%, √2gh (2) 50%, √gh (3) 40%, √2gh (4) 50%, √gh2 JEE Main 2024 (04 Apr Shift 1) JEE Main Previous Year Paper

Q6. A coin is placed on a disc. The coefficient of friction between the coin and the disc is 𝜇. If the distance of the coin from the center of the disc is 𝑟, the maximum angular velocity which can be given to the disc, so that the coin does not slip away, is : JEE Main 2024 (31 Jan Shift 1) JEE Main Previous Year Paper 𝜇𝑔 𝑟 (1) (2) 𝑟 √ 𝜇𝑔 𝜇𝑔 𝜇 (3) (4) √ 𝑟 √𝑟𝑔

Q6. The acceleration due to gravity on the surface of earth is g. If the diameter of earth reduces to half of its original value and mass remains constant, then acceleration due to gravity on the surface of earth would be : (1) g (2) 2g 4 (3) g (4) 4g 2

Q7. Given below are two statements : Statement I : The contact angle between a solid and a liquid is a property of the material of the solid and liquid as well. Statement II : The rise of a liquid in a capillary tube does not depend on the inner radius of the tube. In the light of the above statements, choose the correct answer from the options given below: (1) Statement I is true but Statement II is false. (2) Statement I is false but Statement II is true. (3) Both Statement I and Statement II are false. (4) Both Statement I and Statement II are true.

Q7. Young's modules of material of a wire of length L and cross-sectional area A is Y . If the length of the wire is doubled and cross-sectional area is halved then Young's modules will be: (1) Y (2) 4Y 4 (3) Y (4) 2Y

Q7. A block of ice at -10 °C is slowly heated and converted to steam at 100 °C. Which of the following curves represent the phenomenon qualitatively: JEE Main 2024 (30 Jan Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)

Q7. Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R) Assertion (A) : The property of body, by virtue of which it tends to regain its original shape when the external force is removed, is Elasticity. JEE Main 2024 (27 Jan Shift 2) JEE Main Previous Year Paper Reason (R) : The restoring force depends upon the bonded inter atomic and inter molecular force of solid. In the light of the above statements, choose the correct answer from the options given below : (1) (A) is false but (R) is true (2) (A) is true but (R) is false (3) Both (A) and (R) are true and (R) is the correct (4) Both (A) and (R) are true but (R) is not the explanation (A) correct explanation of (A)

Q7. Pressure inside a soap bubble is greater than the pressure outside by an amount : (given : R = Radius of bubble S = Surface tension of bubble) (1) 2S (2) 4R R S (3) S (4) 4 S R R

Q8. A gas mixture consists of 8 moles of argon and 6 moles of oxygen at temperature 𝑇. Neglecting all vibrational modes, the total internal energy of the system is (1) 29 𝑅𝑇 (2) 20 𝑅𝑇 (3) 27 𝑅𝑇 (4) 21 𝑅𝑇

Q8. Correct Bernoulli's equation is (symbols have their usual meaning) : (1) P + mgh + 12 mv2 = constant (2) P + ρgh + 21 ρv2 = constant (3) P + ρgh + ρv2 = constant (4) P + 12 ρgh + 21 ρv2 = constant JEE Main 2024 (08 Apr Shift 1) JEE Main Previous Year Paper

Q8. The temperature of a gas is −78∘C and the average translational kinetic energy of its molecules is K. The temperature at which the average translational kinetic energy of the molecules of the same gas becomes 2 K is : (1) 127∘C (2) 117∘C (3) −39∘C (4) −78∘C