Practice Questions

Q22.A spherical body of mass 2 kg starting from rest acquires a kinetic energy of 10000 J at the end of 5th second. The force acted on the body is _____ N.

Q22.A particle of mass 10 g moves in a straight line with retardation 2𝑥, where 𝑥 is the displacement in SI units. 10 -𝑛 Its loss of kinetic energy for above displacement is J . The value of 𝑛 will be ________ . 𝑥

Q22.A force of -𝑃 ^𝑘 acts on the origin of the coordinate system. The torque about the point ( 2, - 3 ) is 𝑃(𝑎 ^𝑖+ 𝑏 ^𝑗) 𝑎 𝑥 , The ratio of is The value of 𝑥 is 𝑏 2.

Q22.A thin uniform rod of length 2 m, cross sectional area 𝐴 and density 𝑑 is rotated about an axis passing through the centre and perpendicular to its length with angular velocity 𝜔. If value of 𝜔 in terms of its 𝛼𝐸 rotational kinetic energy 𝐸 is √ 𝐴𝑑, then the value of 𝛼 is ______.

Q22.Three identical resistors with resistance R = 12 Ω and two identical inductors with sell inductance L = 5 mH are connected to an ideal battery with emf of 12 V as shown in figure. The current through the battery long after the switch has been closed will be________ A. JEE Main 2023 (24 Jan Shift 2) JEE Main Previous Year Paper

Q22.A square shaped coil of area 70 cm2 having 600 turns rotates in a magnetic field of 0. 4 Wb m–2 , about an axis which is parallel to one of the side of the coil and perpendicular to the direction of field. If the coil JEE Main 2023 (01 Feb Shift 2) JEE Main Previous Year Paper completes 500 revolution in a minute, the instantaneous emf when the plane of the coil is inclined at 60° with the field, will be ______ V. (Take π = 227 )

Q22.A metallic cube of side 15 cm moving along y-axis at a uniform velocity of 2 m s−1 . In a region of uniform magnetic field of magnitude 0. 5 T directed along z- axis. In equilibrium the potential difference between the faces of higher and lower potential developed because of the motion through the field will be mV.

Q22.Two long parallel wires carrying currents 8 A and 15 A in opposite directions are placed at a distance of 7 cm from each other. A point P is at equidistant from both the wires such that the lines joining the point P to the wires are perpendicular to each other. The magnitude of magnetic field at P is ______ ×10−6 T. (Given: √2 = 1. 4 )

Q23.Match List I and List II List I List II A Microwaves I Physiotherapy B UV rays II Treatment of cancer JEE Main 2023 (31 Jan Shift 2) JEE Main Previous Year Paper C Infra-red rays III Lasik eye surgery D X-rays IV Aircraft navigation Choose the correct answer from the option given below: (1) A-II, B-IV, C-III, D-I (2) A-IV, B-I, C-II, D-III (3) A-IV, B-III, C-I, D-II (4) A-III, B-II, C-I, D-IV

Q23.The electric field and magnetic field components of an electromagnetic wave going through vacuum is described by Ex = E0 sin(kz −ωt) By = B0 sin(kz −ωt) Then the correct relation between E0 and B0 is given by (1) E0B0 = ωk (2) E0 = kB0 (3) kE0 = ωB0 (4) ωE0 = kB0

Q23.A capacitor of capacitance 150. 0 μF is connected to an alternating source of emf given by E = 36 sin(120πt) V. The maximum value of current in the circuit is approximately equal to: (1) 2 A (2) √2 A (3) 2√2 A (4) 1 A √2 → →

Q23.Given below are two statements : Statement I : Electromagnetic waves are not deflected by electric and magnetic field. Statement II : The amplitude of electric field and the magnetic field in electromagnetic waves are related to . each other as E0 = √μ0ε0 B0 In the light of the above statements, choose the correct answer from the options given below: (1) Statement I is true but statement II is false (2) Both Statement I and Statement II are true (3) Statement I is false but statement II is true (4) Both Statement I and Statement II are false

Q23.A coil has an inductance of 2 H and resistance of 4 Ω. A 10 V is applied across the coil. The energy stored in the magnetic field after the current has built up to its equilibrium value will be _____ ×10−2 J

Q23.The general displacement of a simple harmonic oscillator is 𝑥= 𝐴 sin 𝜔𝑡. Let 𝑇 be its time period. The 𝑇 slope of its potential energy (𝑈) – time (𝑡) curve will be maximum when 𝑡= 𝛽. The value of 𝛽 is ______.

Q23.There is an air bubble of radius 1. 0 mm in a liquid of surface tension 0. 075 N m–1 and density 1000 kg m–3 at a depth of 10 cm below the free surface. The amount by which the pressure inside the bubble is greater than the atmospheric pressure is _______ Pa(g = 10 m s−2).

Q23.Two wires each of radius 0 . 2 cm and negligible mass, one made of steel and the other made of brass are loaded as shown in the figure. The elongation of the steel wire is ______10 – 6 m. [Young's modulus for steel = 2 × 1011 N m – 2 and 𝑔= 10 m s – 2] JEE Main 2023 (10 Apr Shift 1) JEE Main Previous Year Paper

Q23.A certain pressure '𝑃' is applied to 1 litre of water and 2 litre of a liquid separately. Water gets compressed to 0 . 01% whereas the liquid gets compressed to 0 . 03%. The ratio of Bulk modulus of water to that of the liquid 3 is 𝑥. The value of 𝑥 is ______.

Q23.A solid sphere of mass 1 kg rolls without slipping on a plane surface. Its kinetic energy is 7 × 10-3 J. The speed of the centre of mass of the sphere is ______ cm s-1.

Q23.In a Young’s double slit experiment, two slits are illuminated with a light of wavelength 800 nm . The line joining A1P is perpendicular to A1A2 as shown in the figure. If the first minimum is detected at P , the value of slits separation a will be : JEE Main 2023 (29 Jan Shift 1) JEE Main Previous Year Paper The distance of screen from slits D = 5 cm . (1) 0. 4 mm (2) 0. 5 mm (3) 0. 2 mm (4) 0. 1 mm

Q23.The waves emitted when a metal target is bombarded with high energy electrons are (1) Microwaves (2) Infrared rays (3) X-rays (4) Radio Waves

Q23.Two plates A and B have thermal conductivities 84 W m-1 K-1 and 126 W m-1 K-1 respectively. They have same surface area and same thickness. They are placed in contact along their surfaces. If the temperatures of the outer surfaces of A and B are kept at 100∘C and 0∘C respectively, then the temperature of the surface of contact in steady state is_____ ∘C.

Q23.The ratio of average electric energy density and total average energy density of electromagnetic wave is: (1) 2 (2) 1 (3) 3 (4) 21

Q23.A wire of length 1 m moving with velocity 8 m s−1 at right angles to a magnetic field of 2 T. The magnitude of induced emf, between the ends of wire will be ___________. (1) 20 V (2) 8 V (3) 12 V (4) 16 V

Q23.A thin prism P1 with an angle 6° and made of glass of refractive index 1. 54 is combined with another prism P2 made from glass of refractive index 1. 72 to produce dispersion without average deviation. The angle of prism P2 is : (1) 6° (2) 1. 3° (3) 7. 8° (4) 4. 5°

Q23.A solid sphere of mass 500 g radius 5 cm is rotated about one of its diameter with angular speed of 10 rad s-1. If the moment of inertia of the sphere about its tangent is 𝑥× 10-2 times its angular momentum about the diameter. Then the value of 𝑥 will be