Practice Questions

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. At what distance above and below the surface of the earth a body will have same weight? (Take radius of earth as R) (1) √5R −R (2) √3R−R 2 (3) R (4) √5R−R 2 2

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

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

Q7. A cube of ice floats partly in water and partly in kerosene oil. The ratio of volume of ice immersed in water to that in kerosene oil (specific gravity of Kerosene oil = 0.8, specific gravity of ice = 0.9) JEE Main 2024 (08 Apr Shift 2) JEE Main Previous Year Paper (1) 1 : 1 (2) 5 : 4 (3) 8 : 9 (4) 9 : 10

Q7. A sphere of relative density σ and diameter D has concentric cavity of diameter d. The ratio of Dd , if it just floats on water in a tank is : (1) ( σ+2σ−2 ) 1/3 (2) ( σ−1σ )1/3 (3) σ−1 1/3 (4) σ+1 1/3 ( σ ) ( σ−1 )

Q7. A simple pendulum doing small oscillations at a place R height above earth surface has time period of T1 = 4 s . T2 would be it's time period if it is brought to a point which is at a height 2R from earth surface. Choose the correct relation [R = radius of earth ] : (1) 2 T1 = T2 (2) 2 T1 = 3 T2 (3) T1 = T2 (4) 3 T1 = 2 T2

Q7. An artillery piece of mass 𝑀1 fires a shell of mass 𝑀2 horizontally. Instantaneously after the firing, the ratio of kinetic energy of the artillery and that of the shell is : 𝑀1 𝑀2 (1) (2) ( 𝑀1 + 𝑀2 ) 𝑀1 (3) 𝑀2 (4) 𝑀1 ( 𝑀1 + 𝑀2 ) 𝑀2

Q7. A metal wire of uniform mass density having length L and mass M is bent to form a semicircular arc and a particle of mass m is placed at the centre of the arc. The gravitational force on the particle by the wire is : (1) GmMπ2 (2) GMmπ L2 2 L2 (3) 0 (4) 2GmMπ L2

Q7. If 𝑅 is the radius of the earth and the acceleration due to gravity on the surface of earth is 𝑔= 𝜋2 m s-2, then the length of the second's pendulum at a height ℎ= 2𝑅 from the surface of earth will be: 2 1 (1) m (2) m 9 9 (3) 4 m (4) 8 m 9 9

Q7. A small spherical ball of radius 𝑟, falling through a viscous medium of negligible density has terminal velocity 𝑣. Another ball of the same mass but of radius 2𝑟, falling through the same viscous medium will have terminal velocity: (1) 𝑣 (2) 𝑣 2 4 (3) 4𝑣 (4) 2𝑣

Q7.Match List-I with List-II : List-I List-II (A) A force that restores an elastic body of unit area to its original state (I) Bulk modulus (B) Two equal and opposite forces parallel to opposite faces (II) Young's modulus Forces perpendicular everywhere to the surface per unit area (C) (III) Stress same everywhere (D) Two equal and opposite forces perpendicular to opposite faces (IV) Shear modulus Choose the correct answer from the options given below : (1) (A)-(IV), (B)-(II), (C)-(III), (D)-(I) (2) (A)-(III), (B)-(IV), (C)-(I), (D)-(II) (3) (A)-(II), (B)-(IV), (C)-(I), (D)-(III) (4) (A)-(III), (B)-(I), (C)-(II), (D)-(IV)

Q7. A wire of length L and radius r is clamped at one end. If its other end is pulled by a force F , its length increases by l. If the radius of the wire and the applied force both are reduced to half of their original values keeping original length constant, the increase in length will become: (1) 3 times (2) 32 times (3) 4 times (4) 2 times

Q7. Two planets A and B having masses m1 and m2 move around the sun in circular orbits of r1 and r2 radii respectively. If angular momentum of A is L and that of B is 3 L, the ratio of time period ( TBTA ) is: (1) r2 32 (2) 1 m2 3 27 ( m1 ) ( r1 ) (3) m1 3 (4) r1 3 27( m2 ) ( r2 )

Q7. A real gas within a closed chamber at 27∘C undergoes the cyclic process as shown in figure. The gas obeys PV 3 = RT equation for the path A to B. The net work done in the complete cycle is (assuming R = 8 J/molK JEE Main 2024 (09 Apr Shift 2) JEE Main Previous Year Paper ): (1) 20 J (2) 205 J (3) −20 J (4) 225 J

Q7. A big drop is formed by coalescing 1000 small droplets of water. The surface energy will become : JEE Main 2024 (01 Feb Shift 2) JEE Main Previous Year Paper (1) 100 times (2) 10 times 1 1 (3) 100th (4) 10th

Q7. To project a body of mass m from earth's surface to infinity, the required kinetic energy is (assume, the radius of earth is RE, g = acceleration due to gravity on the surface of earth): (1) 2mgRE (2) 4mgRE (3) mgRE (4) 1/2mgRE

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

Q8. A diatomic gas (γ = 1.4) does 100 J of work in an isobaric expansion. The heat given to the gas is : (1) 250 J (2) 150 J (3) 350 J (4) 490 J

Q8. A sample of 1 mole gas at temperature T is adiabatically expanded to double its volume. If adiabatic constant for the gas is γ = 32 , then the work done by the gas in the process is: (1) R T [2 −√2] (2) RT [2 + √2] (3) RT [2 −√2] (4) RT[2 + √2]

Q8. In hydrogen like system the ratio of coul0mbian force and gravitational force between an electron and a proton is in the order of : (1) 1039 (2) 1029 (3) 1019 (4) 1036

Q8. A small ball of mass m and density ρ is dropped in a viscous liquid of density ρ0 . After sometime, the ball falls with constant velocity. The viscous force on the ball is : JEE Main 2024 (06 Apr Shift 1) JEE Main Previous Year Paper (1) mg (1 −ρρ0) (2) mg (1 + ρ0ρ ) (3) mg ( ρ0ρ −1) (4) mg(1 −ρ0ρ ) ∇

Q8. Four identical particles of mass 𝑚 are kept at the four corners of a square. If the gravitational force exerted on 2√2 + 1 𝐺𝑚2 one of the masses by the other masses is , the length of the sides of the square is 32 𝐿2 𝐿 (1) (2) 4𝐿 2 (3) 3𝐿 (4) 2𝐿

Q8. A small liquid drop of radius R is divided into 27 identical liquid drops. If the surface tension is T , then the work done in the process will be : (1) 8πR2T (2) 3πR2T (3) 1 πR2T (4) 4πR2T 8

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