Practice Questions

Q23.A man of 60 kg is running on the road and suddenly jumps into a stationary trolly car of mass 120 kg. Then the trolly car starts moving with velocity 2 m s−1 . The velocity of the running man was _____ m s−1 , when he jumps into the car. + m s−1 . The magnitude of

Q23.A block of mass 200 g is kept stationary on a smooth inclined plane by applying a minimum horizontal force 𝐹= √𝑥 N as shown in figure. JEE Main 2022 (25 Jun Shift 2) JEE Main Previous Year Paper The value of 𝑥= _____.

Q23.In an experiment to determine the velocity of sound in air at room temperature using a resonance tube, the first resonance is observed when the air column has a length of 20. 0 cm for a tuning fork of frequency 400 Hz is used. The velocity of the sound at room temperature is 336 m s−1 . The third resonance is observed when the air column has a length of _____ cm

Q23.A monoatomic gas performs a work of Q where Q is the heat supplied to it. The molar heat capacity of the gas 4 will be _____ R during this transformation. Where R is the gas constant.

Q23.A wire of length 𝐿 and radius 𝑟 is clamped rigidly at one end. When the other end of the wire is pulled by a force 𝐹, its length increases by 5 cm. Another wire of the same material of length 4 L and radius 4𝑟 is pulled by a force 4 𝐹 under same conditions. The increase in length of this wire is _____ cm.

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.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 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.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.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 metre scale is balanced on a knife edge at its centre. When two coins, each of mass 10 g are put one on the top of the other at the 10. 0 cm mark the scale is found to be balanced at 40. 0 cm mark. The mass of the metre scale is found to be x × 10−2 kg. The value of x is _____ . Q24. 0. 056 kg of Nitrogen is enclosed in a vessel at a temperature of 127°C. The amount of heat required to double the speed of its molecules is_____ kcal. (Take R = 2 cal mole −1 K−1 )

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.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.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.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.A batsman hits back a ball of mass 0. 4 kg straight in the direction of the bowler without changing its initial speed of 15 m s−1 . The impulse imparted to the ball is _____ N s .

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

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 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 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.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.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

Q24.Moment of Inertia (M.I.) of four bodies having same mass 𝑀 and radius 2𝑅 are as follows 𝐼1 = M.I. of solid sphere about its diameter 𝐼2 = M.I. of solid cylinder about its axis 𝐼3 = M.I. of solid circular disc about its diameter 𝐼4 = M.I. of thin circular ring about its diameter If 2𝐼2 + 𝐼3 + 𝐼4 = 𝑥𝐼1 then the value of 𝑥 will be _____ .

Q24.The position vector of 1 kg object is →r= (3ˆi −ˆj) m and its velocity →v= (3ˆj ˆk) its angular momentum is √x N m s, where x is

Q24.The displacement current of 4. 425 μA is developed in the space between the plates of parallel plate capacitor when voltage is changing at a rate of 106 V s−1 . The area of each plate of the capacitor is 40 cm2 . The distance between each plate of the capacitor is x × 10−3 m . The value of x is , (Permittivity of free space, ε0 = 8. 85 × 10−12 C2 N−1 m−2 ) _______