Practice Questions

Q23.The volume V of a given mass of monoatomic gas changes with temperature T according to the relation 2 V = KT 3 . The workdone when temperature changes by 90 K will be xR. The value of x is [ R universal gas constant ]

Q23.A rod of mass M and length L is lying on a horizontal frictionless surface. A particle of mass m travelling along the surface hits at one end of the rod with a velocity u in a direction perpendicular to the rod. The collision is completely elastic. After collision, particle comes to rest. The ratio of masses ( Mm ) is x1 . The value of x will be

Q23.A parallel plate capacitor of capacitance 200𝜇F is connected to a battery of 200 V . A dielectric slab of dielectric constant 2 is now inserted into the space between plates of capacitor while the battery remain connected. The change in the electrostatic energy in the capacitor will be __________ J .

Q23.As shown in the figure, a block of mass √3 kg is kept on a horizontal rough surface of coefficient of friction 1 . The critical force to be applied on the vertical surface as shown at an angle 60° with horizontal such that 3√3 it does not move, will be 3x. The value of x will = 10 m s−2; sin 60°= √32 ; cos 60°= 21 ] [g

Q23.A force F = 4ˆi + 3ˆj + 4ˆk is applied on an intersection point of x = 2 plane and x -axis. The magnitude of torque of this force about a point (2, 3, 4) is ________. (Round off to the Nearest Integer)

Q23.The water is filled up to a height of 12 m in a tank having vertical sidewalls. A hole is made in one of the walls at a depth h below the water level. The value of h for which the emerging stream of water strikes the ground at the maximum range is _____ m .

Q23.A body rotating with an angular speed of 600 rpm is uniformly accelerated to 1800 rpm in 10 sec. The number of rotations made in the process is

Q23.In the reported figure, two bodies 𝐴 and 𝐵 of masses 200 g and 800 g are attached with the system of springs. Springs are kept in a stretched position with some extension when the system is released. The horizontal surface is assumed to be frictionless. The angular frequency will be _______ rad s-1 when 𝑘= 20 N m-1.

Q23.A ball with a speed of 9 m s-1 collides with another identical ball at rest. After the collision, the direction of each ball makes an angle of 30° with the original direction. If the ratio of velocities of the balls after the collision is 𝑥: 𝑦, then what is the value of 𝑥?

Q23.A uniform metallic wire is elongated by 0. 04 m when subjected to a linear force F. The elongation, if its length and diameter is doubled and subjected to the same force will be _________ cm.

Q23.As shown in the figure, a particle of mass 10 kg is placed at a point A. When the particle is slightly displaced to its right, it starts moving and reaches the point B. The speed of the particle at B is x m s−1 . (Take g = 10 m s−2) The value of x to the nearest integer is

Q24.Consider a water tank as shown in the figure. It's cross-sectional area is 0. 4 m2 . The tank has an opening B near the bottom whose cross-section area is 1 cm2 . A load of 24 kg is applied on the water at the top when the height of the water level is 40 cm above the bottom, the velocity of water coming out the opening B is v m s−1 . The value of v, to the nearest integer, is ___ .[Take the value of g to be 10 m s−2 ]

Q24.Consider an electrical circuit containing a two way switch S. Initially S is open and then T1 is connected to T2. As the current in R = 6 Ω attains a maximum value of steady-state level, T1 is disconnected from T2 and JEE Main 2021 (27 Jul Shift 1) JEE Main Previous Year Paper immediately connected to T3. Potential drop across r = 3 Ω resistor immediately after T1 is connected to T3 is ______V. (Round off to the Nearest Integer)

Q24.A 16 Ω wire is bent to form a square loop. A 9 V supply having an internal resistance of 1 Ω is connected across one of its sides. The potential drop across the diagonals of the square loop is __________ ×10−1 V .

Q24.The radius in kilometer to which the present radius of earth (R = 6400 km) to be compressed so that the escape velocity is increased 10 time is _______.

Q24.A particle of mass 1 kg is hanging from a spring of force constant 100 N m−1. The mass is pulled slightly downward and released so that it executes free simple harmonic motion with time period T. The time when the kinetic energy and potential energy of the system will become equal, is T n . The value of n is ________. JEE Main 2021 (31 Aug Shift 1) JEE Main Previous Year Paper

Q24.A monoatomic gas of mass 4. 0 u is kept in an insulated container. The container is moving with velocity 30 m s−1 . If the container is suddenly stopped then a change in temperature of the gas ( R = gas constant) is 3Rx . Value of x is, → 3 4 N C−1 . The ratio of flux of reported field

Q24.Two simple harmonic motion, are represented by the equations 3πt + √3 cos y1 = 10 sin(3πt + π3 ); y2 = 5(sin 3πt) Ratio of amplitude of y1 to y2 = x : 1 . The value of x is

Q24.The centre of a wheel rolling on a plane surface moves with a speed v0. A particle on the rim of the wheel at the same level as the centre will be moving at a speed √xv0. Then the value of x is .

Q24.A soap bubble of the radius 3 cm is formed inside another soap bubble of radius, 6 cm . The radius of an equivalent soap bubble that has the same excess pressure as inside the smaller bubble with respect to the atmospheric pressure is____ cm.

Q24.The root-mean-square speed of molecules of a given mass of a gas at 27 °C and 1 atmosphere pressure is 200 m s−1. The root-mean-square speed of molecules of the gas at 127 °C and 2 atmosphere pressure is x m s−1. The value of x will be __________. √3

Q24.Two waves are simultaneously passing through a string and their equations are : y1 = A1 sin k(x −vt), y2 = A2 sin k(x −vt + x0). Given amplitudes A1 = 12 mm and A2 = 5 mm, x0 = 3. 5 cm and wave number k = 6. 28 cm−1. The amplitude of resulting wave will be _____ mm.

Q24.A ball of mass 10 kg moving with a velocity 10√3 m s−1 along X -axis, hits another ball of mass 20 kg which is at rest. After the collision, the first ball comes to rest and the second one disintegrates into two equal pieces. One of the pieces starts moving along Y -axis at a speed of 10 m s−1 . The second piece starts moving at a speed of 20 m s−1 at an angle θ (degree) with respect to the X -axis. The configuration of pieces after the collision is shown in the figure. The value of θ to the nearest integer is _________.

Q24.A rod CD of thermal resistance 10. 0 KW−1 is joined at the middle of an identical rod AB as shown in figure. The ends A, B and D are maintained at 200°C, 100°C and 125°C respectively. The heat current in CD is JEE Main 2021 (27 Aug Shift 1) JEE Main Previous Year Paper P W. The value of P is

Q24.A hydraulic press can lift 100 kg when a mass 𝑚 is placed on the smaller piston. It can lift kg when the diameter of the larger piston is increased by 4 times and that of the smaller piston is decreased by 4 times keeping the same mass 𝑚 on the smaller piston.