Practice Questions

Q21.A ball of mass 0. 5 kg is dropped from the height of 10 m . The height, at which the magnitude of velocity becomes equal to the magnitude of acceleration due to gravity, is _____ m. [Use g = 10 m s−2 ]

Q21.Two inclined planes are placed as shown in figure. A block is projected from the Point A of inclined plane AB along its surface with a velocity just sufficient to carry it to the top Point B at a height 10 m. After reaching the Point B the block slides down on inclined plane + BC . Time it takes to reach to the point C from point A is t(√2 1)s. The value of t is _____ (use g = 10 m s−2 )

Q21.A car is moving with speed of 150 km h-1 and after applying the brake it will move 27 m before it stops. If the same car is moving with a speed of one third the reported speed then it will stop after travelling _____ m distance.

Q21.A body is projected from the ground at an angle of 45° with the horizontal. Its velocity after 2 s is 20 m s−1 . The maximum height reached by the body during its motion is _____ m . (use g = 10 m s−2 )

Q21.In an experiment to find acceleration due to gravity (g) using simple pendulum, time period of 0. 5 s is measured from time of 100 oscillation with a watch of 1 s resolution. If measured value of length is 10 cm known to 1 mm accuracy. The accuracy in the determination of g is found to be x%. The value of x is

Q21.A particle is moving in a straight line such that its velocity is increasing at 5 m s−1 per meter. The acceleration of the particle is _____ m s−2 at a point where its velocity is 20 m s−1 .

Q21.A ball of mass m is thrown vertically upward. Another ball of mass 2 m is thrown an angle θ with the vertical. Both the balls stay in air for the same period of time. The ratio of the heights attained by the two balls respectively is 1 . The value of x is _____ . x

Q21.A uniform chain of 6 m length is placed on a table such that a part of its length is hanging over the edge of the table. The system is at rest. The co-efficient of static friction between the chain and the surface of the table is 0 . 5, the maximum length of the chain hanging from the table is _____ m.

Q21.An object is projected in the air with initial velocity u at an angle θ. The projectile motion is such that the horizontal range R, is maximum. Another object is projected in the air with a horizontal range half of the range of first object. The initial velocity remains same in both the case. The value of the angle of projection, at which the second object is projected, will be _____ degree.

Q21.If the projection of 2 ^𝑖+ 4 ^𝑗- 2 ^𝑘 on ^𝑖+ 2 ^𝑗+ 𝛼 ^𝑘 is zero. Then, the value of 𝛼 will be

Q21.A car covers AB distance with first one-third at velocity v1 m s−1 , second one-third at v2 m s−1 and last one- third at v3 m s−1 . If v3 = 3v1, v2 = 2v1 and v1 = 11 m s−1 , then the average velocity of the car is _____ m s−1 .

Q21.As per the given figure, two plates A and B of thermal conductivity K and 2K are joined together to form a compound plate. The thickness of plates are 4. 0 cm and 2. 5 cm respectively and the area of cross-section is 120 cm2 for each plate. The equivalent thermal conductivity of the compound plate is (1 + α5 )K , then the value of α will be _____ . Q22. 300 calories of heat is given to a heat engine, and it rejects 225 calories of heat. If source temperature is 227°C, then the temperature of sink will be _____ ∘C.

Q21.A ball is projected vertically upward with an initial velocity of 50 m s−1 at t = 0 s. At t = 2 s, another ball is projected vertically upward with same velocity. At t =____ s, second ball will meet the first ball (g = 10 m s−2) .

Q21.From the top of a tower, a ball is thrown vertically upward which reaches the ground in 6 s. A second ball thrown vertically downward from the same position with the same speed reaches the ground in 1. 5 s. A third JEE Main 2022 (24 Jun Shift 1) JEE Main Previous Year Paper ball released, from the rest from the same location, will reach the ground in _____ s.

Q22.A block of mass '𝑚' (as shown in figure) moving with kinetic energy 𝐸 compresses a spring through a distance 25 cm when, its speed is halved. The value of spring constant of used spring will be 𝑛𝐸 N m-1 for 𝑛= _____.

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.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 ]

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 rolling wheel of 12 kg is on an inclined plane at position P and connected to a mass of 3 kg through a string of fixed length and pulley as shown in figure. Consider PR as friction free surface. The velocity of centre of mass of the wheel when it reaches at the bottom Q of the inclined plane PQ will be 1 √xgh m s−1 . The value of x (rounded off to the nearest integer) is _____. 2

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 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.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 small spherical ball of radius 0. 1 mm and density 104 kg m−3 falls freely under gravity through a distance h before entering a tank of water. If, after entering the water the velocity of ball does not change and it JEE Main 2022 (29 Jun Shift 2) JEE Main Previous Year Paper continue to fall with same constant velocity inside water, then the value of h will be ____ m. (Given g = 10 m s−2 , viscosity of water = 1. 0 × 10−5 N‐s m−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.A fighter jet is flying horizontally at a certain altitude with a speed of 200 m s−1 . When it passes directly overhead an anti-aircraft gun, a bullet is fired from the gun, at an angle θ with the horizontal, to hit the jet. If the bullet speed is 400 m s−1 , the value of θ will be _____ °.