Practice Questions

Q22.A ball of mass 100 g is dropped from a height h = 10 cm on a platform fixed at the top of a vertical spring (as shown in figure). The ball stays on the platform and the platform is depressed by a distance h . The spring 2 constant is _____ N m−1 (Use g = 10 m s−2 )

Q22.Three identical spheres each of mass M are placed at the corners of a right angled triangle with mutually perpendicular sides equal to 3 m each. Taking point of intersection of mutually perpendicular sides as origin, the magnitude of position vector of centre of mass of the system will be √x m. The value of x is JEE Main 2022 (25 Jul Shift 2) JEE Main Previous Year Paper

Q22.Four forces are acting at a point 𝑃 in equilibrium as shown in figure. The ratio of force 𝐹1 to 𝐹2 is 1: 𝑥 where 𝑥= _____ . JEE Main 2022 (25 Jul Shift 1) JEE Main Previous Year Paper

Q22.A system to 10 balls each of mass 2 kg are connected via massless and unstretchable string. The system is allowed to slip over the edge of a smooth table as shown in figure. Tension on the string between the 7th and 8th ball is _____ N when 6th ball just leaves the table.

Q22.A curved in a level road has a radius 75 m. The maximum speed of a car turning this curved road can be 30 m s-1 without skidding. If radius of curved road is changed to 48 m and the coefficient of friction between the tyres and the road remains same, then maximum allowed speed would be _____ m s-1.

Q22.A uniform disc with mass M = 4 kg and radius R = 10 cm is mounted on a fixed horizontal axle as shown in figure. A block with mass m = 2 kg hangs from a massless cord that is wrapped around the rim of the disc. During the fall of the block, the cord does not slip and there is no friction at the axle. The tension in the cord is _____ N . (Take g = 10 ms−2 ) JEE Main 2022 (28 Jun Shift 2) JEE Main Previous Year Paper

Q22.If the initial velocity in horizontal direction of a projectile is unit vector ˆi and the equation of trajectory is y = 5x(1 −x). The y component vector of the initial velocity is _____ ˆj (Take g = 10 m s−2 )

Q22.A ball is thrown vertically upwards with a velocity of 19. 6 m s−1 from the top of a tower. The ball strikes the ground after 6 s. The height from the ground up to which the ball can rise will be ( k5 ) m. The value of k is _____ (use g = 9. 8 m s−2 )

Q22.A solid cylinder length is suspended symmetrically through two massless strings, as shown in the figure. The distance from the initial rest position, the cylinder should be unbinding the strings to achieve a speed of 4 m s−1 , is _____ cm. (take g = 10 m s−2 )

Q22.The area of cross-section of a large tank is 0. 5 m2 . It has a narrow opening near the bottom having area of cross-section 1 cm2 . A load of 25 kg is applied on the water at the top in the tank. Neglecting the speed of water in the tank, the velocity of the water, coming out of the opening at the time when the height of water level in the tank is 40 cm above the bottom, will be _____ cm s−1 . [Take g = 10 m s−2 ]

Q23.The distance of centre of mass from end A of a one dimensional rod (AB) having mass density ρ = kg m−1 and length L (in meter) is 3Lα m. The value of α is _____ (where x is the distance ρ0(1 −x2L2 ) form end A ) JEE Main 2022 (28 Jul Shift 2) JEE Main Previous Year Paper

Q23.A body is performing simple harmonic with an amplitude of 10 cm. The velocity of the body was tripled by air Jet when it is at 5 cm from its mean position. The new amplitude of vibration is √x cm. The value of x is _____ .

Q23.A block of ice of mass 120 g at temperature 0°C is put in 300 g of water at 25°C . The x g of ice melts as the temperature of the water reaches 0°C. The value of x is [Use: Specific heat capacity of water = 4200 J kg−1 K−1 , Latent heat of ice = 3. 5 × 105 J kg−1 ]

Q23.The pressure P1 and density d1 of diatomic gas (γ = 75 ) changes suddenly to P2(> P1) and d2 respectively during an adiabatic process. The temperature of the gas increases and becomes____times of its initial temperature. (given d2 = 32) d1

Q23.In a carnot engine, the temperature of reservoir is 527°C and that of sink is 200 K . If the workdone by the engine when it transfers heat from reservoir to sink is 12000 kJ , the quantity of heat absorbed by the engine from reservoir is _____ ×106 J.

Q23.A 0 . 5 kg block moving at a speed of 12 ms-1 compresses a spring through a distance 30 cm when its speed is halved. The spring constant of the spring will be _____ Nm-1 JEE Main 2022 (25 Jun Shift 1) JEE Main Previous Year Paper

Q23.A square aluminium (shear modulus is 25 × 109 Nm−2 ) slab of side 60 cm and thickness 15 cm is subjected to a shearing force (on its narrow face) of 18. 0 × 104 N . The lower edge is riveted to the floor. The displacement of the upper edge is _____ μm.

Q23.A disc of mass 1 kg and radius R is free of rotate about a horizontal axis passing through its centre and perpendicular to the plane of disc. A body of same mass as that of disc is fixed at the highest point of the disc. Now the system is released, when the body comes to the lowest position, its angular speed will be 4√x3R rad s−1 where x = _____ .

Q23.A liquid of density 750 kg m−3 flows smoothly through a horizontal pipe that tapers in cross-sectional area from A1 = 1. 2 × 10−2 m2 to A2 = A12 . The pressure difference between the wide and narrow sections of the pipe is 4500 Pa . The rate of flow of liquid is _____ ×10−3 m3 s−1 .

Q23.A uniform heavy rod of mass 20 kg. Cross sectional area 0 . 4 m2 and length 20 m is hanging from a fixed support. Neglecting the lateral contraction, the elongation in the rod due to its own weight is 𝑥× 10-9 m. The value of 𝑥 is _____ . (Given. Young's modulus 𝑌= 2 × 1011Nm-2 and 𝑔= 10 m s-2 )

Q23.A diatomic gas (γ = 1. 4) does 400 J of work when it is expanded isobarically. The heat given to the gas in the process is _____ J.

Q23.The elongation of a wire on the surface of the earth is 10−4 m. The same wire of same dimensions is elongated by 6 × 10−5 m on another planet. The acceleration due to gravity on the planet will be _____ m s−2 . (Take acceleration due to gravity on the surface of earth = 10 m s−2 )

Q23.The velocity of a small ball of mass 0 . 3 g and density 8 g cc-1 when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is 1 . 3 g cc-1, then the value of viscous force acting on the ball will be 𝑥× 10-4 N, the value of 𝑥 is _____ . [use 𝑔= 10 m s-2]

Q23.In an experiment to determine the Young's modulus, steel wires of five different lengths ( 1, 2, 3, 4 and 5 ) but of same cross-section (2 mm2) were taken and curves between extension and load were obtained. The slope JEE Main 2022 (27 Jul Shift 2) JEE Main Previous Year Paper (extension/load) of the curves were plotted with the wire length and the following graph is obtained. If the Young's modulus of given steel wires is x × 1011N m−2 , then the value of x is _____ .

Q23.Four identical discs each of mass '𝑀' and diameter '𝑎' are arranged in a small plane as shown in figure. If the 𝑥 will be _____ . moment of inertia of the system about 𝑂𝑂' is 4𝑀𝑎2.𝑥 Then, the value of