Practice Questions

Q24.A soap bubble is blown to a diameter of 7 cm.36960erg of work is done in blowing it further. If surface tension of soap solution is 40dyne/cm then the new radius is______ cm Take (π = 227 )

Q24.An object of mass 0.2 kg executes simple harmonic motion along x axis with frequency of ( 25π )Hz. At the position x = 0.04 m the object has kinetic energy 0.5 J and potential energy 0.4 J. The amplitude of oscillation is _____ cm .

Q24.A closed and an open organ pipe have same lengths. If the ratio of frequencies of their seventh overtones is ( a−1a ) then the value of a is ________ → 2^i+6^j+8^k 2^i+^j+^k . The

Q24.The time period of simple harmonic motion of mass 𝑀 in the given figure is 𝜋√ 𝛼𝑀5𝐾, where the value of _______. JEE Main 2024 (31 Jan Shift 2) JEE Main Previous Year Paper

Q24.A particle executes simple harmonic motion with an amplitude of 4 cm . At the mean position, velocity of the particle is 10 cm s−1 . The distance of the particle from the mean position when its speed becomes 5 cm s−1 is √α cm , where α =______. JEE Main 2024 (27 Jan Shift 1) JEE Main Previous Year Paper

Q25.Three infinitely long charged thin sheets are placed as shown in figure. The magnitude of electric field at the point P is xσ . The value of x is _______ (all quantities are measured in SI units). ϵo JEE Main 2024 (06 Apr Shift 1) JEE Main Previous Year Paper

Q25.A capacitor of capacitance C and potential V has energy E. It is connected to another capacitor of capacitance 2C and potential 2V . Then the loss of energy is x3 E , where x is _______.

Q25.A parallel plate capacitor with plate separation 5 mm is charged up by a battery. It is found that on introducing a dielectric sheet of thickness 2 mm, while keeping the battery connections intact, the capacitor draws 25% more charge from the battery than before. The dielectric constant of the sheet is ____.

Q25.The distance between charges +𝑞 and -𝑞 is 2𝑙 and between +2𝑞 and -2𝑞 is 4𝑙. The electrostatic potential at point 𝑃 at a distance 𝑟 from centre 𝑂 is -𝛼𝑞𝑙 × 109 V, where the value of 𝛼 is ______. (Use 𝑟2 1 = 9 × 109 N m2 C-2) 4𝜋𝜀0 2

Q25.A parallel plate capacitor of capacitance 12.5pF is charged by a battery connected between its plates to potential difference of 12.0 V. The battery is now disconnected and a dielectric slab (ϵr = 6) is inserted between the plates. The change in its potential energy after inserting the dielectric slab is _____ 10−12 J.

Q25.Two identical charged spheres are suspended by strings of equal lengths. The strings make an angle 𝜃 with each other. When suspended in water the angle remains the same. If density of the material of the sphere is 1 . 5 g / cc, the dielectric constant of water will be ______. (Take density of water = 1 g / cc)

Q25.If the net electric field at point P along Y axis is zero, then the ratio of q2 is 8 , where x = _____. q3 5√x

Q25.The electric field at point p due to an electric dipole is E. The electric field at point R on equitorial line will be E . The value of x : x

Q25.At the centre of a half ring of radius R = 10 cm and linear charge density 4nCm−1 , the potential is xπV . The value of x is _______ JEE Main 2024 (09 Apr Shift 1) JEE Main Previous Year Paper

Q25.The electric field between the two parallel plates of a capacitor of 1.5μF capacitance drops to one third of its initial value in 6.6μs when the plates are connected by a thin wire. The resistance of this wire is _____ Ω . (Given, log 3 = 1.1 )

Q25.Suppose a uniformly charged wall provides a uniform electric field of 2 × 104 N C-1 normally. A charged particle of mass 2 g being suspended through a silk thread of length 20 cm and remain stayed at a distance 1 of 10 cm from the wall. Then the charge on the particle will be 𝜇C where 𝑥= ________ [use √x 𝑔= 10 m s-2]

Q25.A particle of mass 0.50 kg executes simple harmonic motion under force F = −50 (Nm−1)x. The time period of oscillation is 35 x s. The value of x is _______ (Given π = 227 )

Q25.In the given circuit, the current flowing through the resistance 20 Ω is 0. 3 A, while the ammeter reads 0. 9 A. The value of R1 is _____ Ω .

Q25.An infinite plane sheet of charge having uniform surface charge density +σsC/m2 is placed on x −y plane. Another infinitely long line charge having uniform linear charge density +λeC/m is placed at z = 4 m plane and parallel to y-axis. If the magnitude values |σs| = 2 |λe| then at point (0, 0, 2), the ratio of magnitudes of electric field values due to sheet charge to that of line charge is π√n : 1. The value of n is_______.

Q26.The charge accumulated on the capacitor connected in the following circuit is ______ μC. (Given C = 150 μF)

Q26.A wire of resistance R and radius r is stretched till its radius became r/2. If new resistance of the stretched wire is xR, then value of x is _______ →

Q26.Two charges of -4 μC and +4 μC are placed at the points 𝐴( 1, 0, 4 ) m and 𝐵( 2, - 1, 5 ) m located in an electric field →𝐸= 0 . 20 ^i V cm-1. The magnitude of the torque acting on the dipole is 8√𝛼× 10-5 N m, where 𝛼= _________.

Q26.Equivalent resistance of the following network is ________ 𝛺.

Q26.Two wires A and B are made up of the same material and have the same mass. Wire A has radius of 2.0 mm and wire B has radius of 4.0 mm. The resistance of wire B is 2Ω. The resistance of wire A is _____ Ω. JEE Main 2024 (04 Apr Shift 2) JEE Main Previous Year Paper

Q26.A 16 Ω wire is bend to form a square loop. A 9 V battery with internal resistance 1 Ω is connected across one of its sides. If a 4 μF capacitor is connected across one of its diagonals, the energy stored by the capacitor will be x 2 μJ, where x =______.