Practice Questions

Q4. A solid spherical ball is rolling on a frictionless horizontal plane surface about its axis of symmetry. The ratio of rotational kinetic energy of the ball to its total kinetic energy is (1) 1 (2) 2 5 5 (3) 2 (4) 7 7 10

Q4. A ball is projected with kinetic energy E , at an angle of 60° to the horizontal. The kinetic energy of this ball at the highest point of its flight will become : (1) Zero (2) E 2 (3) E (4) E 4

Q4. In two different experiments, an object of mass 5 kg moving with a speed of 25 ms-1 hits two different walls and comes to rest within (i) 3 second, (ii) 5 seconds, respectively. Choose the correct option out of the following : (1) Impulse and average force acting on the object (2) Impulse will be same for both the cases but the will be same for both the cases. average force will be different. (3) Average force will be same for both the cases but (4) Average force and impulse will be different for the impulse will be different. both the cases.

Q4. A body of mass 8 kg and another of mass 2 kg are moving with equal kinetic energy. The ratio of their respective momenta will be (1) 1: 1 (2) 2: 1 (3) 1: 4 (4) 4: 1

Q4. A block of mass 10 kg starts sliding on a surface with an initial velocity of 9. 8 ms−1 . The coefficient of friction between the surface and block is 0. 5 . The distance covered by the block before coming to rest is :[use g = 9. 8 ms−2 ] (1) 9. 8 m (2) 4. 9 m (3) 12. 5 m (4) 19. 6 m →Q5. + x −y plane. Assume distance in A particle experiences a variable force F = (4xˆi 3y2ˆj) in a horizontal meters and force is newton. If the particle moves from point (1, 2) to point (2, 3) in the x −y plane, then Kinetic Energy changes by : (1) 25 J (2) 50 J (3) 12. 5 J (4) 0 J

Q5. Two blocks of masses 10 kg and 30 kg are placed on the same straight line with coordinates (0, 0) cm and (x, 0) cm respectively. The block of 10 kg is moved on the same line through a distance of 6 cm towards the other block. The distance through which the block of 30 kg must be moved to keep the position of centre of mass of the system unchanged is (1) 4 cm towards the 10 kg block (2) 2 cm away from the 10 kg block (3) 2 cm towards the 10 kg block (4) 4 cm away from the 10 kg block

Q5. In the given figure, the block of mass m is dropped from the point ′A′ . The expression for kinetic energy of block when it reaches point ′B′ is (1) mgy0 (2) 12 mgy20 (3) 1 mgy2 (4) mg(y −y0) 2

Q5. If momentum of a body is increased by 20%, then its kinetic energy increases by : (1) 36% (2) 40% (3) 44% (4) 48%

Q5. The height of any point 𝑃 above the surface of earth is equal to diameter of earth. The value of acceleration due to gravity at point 𝑃 will be : (Given 𝑔= acceleration due to gravity at the surface of earth). (1) 𝑔 (2) 𝑔 2 4 𝑔 𝑔 (3) (4) 3 9

Q5. Two planets A and B of equal mass are having their period of revolutions TA and TB such that TA = 2TB . These planets are revolving in the circular orbits of radii rA and rB respectively. Which out of the following would be the correct relationship of their orbits? (1) 2r2A = r3B (2) r3A = 2r3B (3) r3A = 4r3B (4) T A2 −T B2 = GMπ2 (r3B −4r3A)

Q5. The percentage decrease in the weight of a rocket, when taken to a height of 32 km above the surface of earth will, be (Radius of earth = 6400 km) (1) 1% (2) 3% (3) 4% (4) 0. 5%

Q6. Two objects of equal masses placed at certain distance from each other attracts each other with a force of F . If one-third mass of one object is transferred to the other object, then the new force will be JEE Main 2022 (28 Jun Shift 2) JEE Main Previous Year Paper (1) 2 F (2) 16 F 9 9 (3) 8 F (4) F 9

Q6. If p is the density and η is coefficient of viscosity of fluid which flows with a speed v in the pipe of diameter d, the correct formula for Reynolds number Re is (1) Re = πdρv (2) Re = ηdρv (3) Re = ρvdη (4) Re = ρνdη

Q6. The terminal velocity 𝑣𝑡 of the spherical rain drop depends on the radius 𝑟 of the spherical rain drop as (1) 𝑟 (2) 𝑟2 1 1 (3) (4) 𝑟 𝑟2

Q6. The distance between Sun and Earth is R. The duration of year if the distance between Sun and Earth becomes 3R will be : (1) √3 yr (2) 3√3 yr (3) 3 yr (4) 9 yr

Q7. The ratio of specific heats in terms of degree of freedom 𝑓 is given by : 𝐶𝑉 (1) 1 + 𝑓 (2) 1 + 2 3 𝑓 (3) 1 + 𝑓 (4) 1 + 1 2 𝑓

Q7. A flask contains argon and oxygen in the ratio of 3 : 2 in mass and the mixture is kept at 27°C . The ratio of their average kinetic energy per molecule respectively (1) 3 : 5 (2) 9 : 4 (3) 2 : 3 (4) 1 : 1

Q7. An object is taken to a height above the surface of earth at a distance 5 R from the centre of the earth. Where 4 radius of earth, R = 6400 km. The percentage decrease in the weight of the object will be JEE Main 2022 (25 Jul Shift 2) JEE Main Previous Year Paper (1) 36% (2) 50% (3) 64% (4) 25%

Q7. If the length of a wire is made double and radius is halved of its respective values. Then, the Young's modulus of the material of the wire will : (1) Remain same (2) Become 8 times its initial value (3) Become 1th of its initial value (4) Become 4 times its initial value 4

Q8. In the figure, a very large plane sheet of positive charge is shown. 𝑃1 and 𝑃2 are two points at distance 𝑙 and 2𝑙 from the charge distribution. If 𝜎 is the surface charge density, then the magnitude of electric fields 𝐸1 and 𝐸2 at 𝑃1 and 𝑃2 respectively are JEE Main 2022 (25 Jun Shift 1) JEE Main Previous Year Paper 𝜎 𝜎 2𝜎 𝜎 (1) 𝐸1 = 𝜀𝑜, 𝐸2 = 2𝜀𝑜 (2) 𝐸1 = 𝜀𝑜, 𝐸2 = 𝜀𝑜 𝜎 𝜎 (3) 𝐸1 = 𝐸2 = (4) 𝐸1 = 𝐸2 = 2𝜀𝑜 𝜀𝑜

Q8. Two metallic blocks M1 and M2 of same area of cross-section are connected to each other (as shown in figure). If the thermal conductivity of M2 is K then the thermal conductivity of M1 will be : [Assume steady state heat conduction] JEE Main 2022 (24 Jun Shift 1) JEE Main Previous Year Paper (1) 10K (2) 8K (3) 12. 5K (4) 2K

Q8. A radar sends an electromagnetic signal of electric field (E0) = 2. 25 V m−1 and magnetic field (B0) = 1. 5 × 10−8 T which strikes a target on line of sight at a distance of 3 km in a medium. After that, a part of signal (echo) reflects back towards the radar with same velocity and by same path. If the signal was transmitted at time t = 0 from radar, then after how much time echo will reach to the radar? (1) 2. 0 × 10−5 s (2) 4. 0 × 10−5 s (3) 1. 0 × 10−5s (4) 8. 0 × 10−5s

Q8. A monoatomic gas at pressure P and volume V is suddenly compressed to one eighth of its original volume. The final pressure at constant entropy will be (1) P (2) 8P (3) 32P (4) 64P

Q9. When a particle executes simple Harmonic motion, the nature of graph of velocity as function of displacement will be (1) Circular (2) Ellipitical (3) Sinusoidal (4) Straight line

Q9. In the wave equation 𝑦= 0 . 5sin 𝜆400𝑡- 𝑥𝑚 the velocity of the wave will be : (1) 200 m s-1 (2) 200√2 m s-1 (3) 400 m s-1 (4) 400√2 m s-1