Practice Questions

Q28.A coil of 200 turns and area 0 . 20 m2 is rotated at half a revolution per second and is placed in uniform magnetic field of 0 . 01 T perpendicular to axis of rotation of the coil. The maximum voltage generated in the 2𝜋 coil is volt. The value of 𝛽 is ______. 𝛽 ∘

Q28.The current of 5 A flows in a square loop of sides 1 m is placed in air. The magnetic field at the centre of the loop is X√2 × 10-7 T. The value of X is _________.

Q28.A square loop of side 10 cm and resistance 0. 7 Ω is placed vertically in the east-west plane. A uniform magnetic field of 0. 20 T is set up across the plane in the north-east direction. The magnetic field is decreased to zero in 1 s at a steady rate. Then, the magnitude of induced emf is √x × 10−3 V . The value of x is _______.

Q28.The horizontal component of earth's magnetic field at a place is 3. 5 × 10−5 T. A very long straight conductor carrying current of √2 A in the direction from South east to North West is placed. The force per unit length experienced by the conductor is ________ ×10−6 N m−1 .

Q28.In the given figure, the charge stored in 6μF capacitor, when points A and B are joined by a connecting wire is _______ μC. o

Q28.An alternating emf E = 110√2 sin 100t volt is applied to a capacitor of 2μF, the rms value of current in the circuit is _____ mA ,

Q28.Two coils have mutual inductance 0. 002 H. The current changes in the first coil according to the relation i = i0sinωt, where i0 = 5 A and ω = 50π rad s−1 . The maximum value of emf in the second coil is απ V . The value of α is

Q28.When a coil is connected across a 20 V dc supply, it draws a current of 5 A. When it is connected across 20 V, 50 Hz ac supply, it draws a current of 4 A. The self inductance of the coil is ______ mH . ( Take π = 3 )

Q28.A series LCR circuit with 𝐿= 100 mH, 𝐶= 10-3 F and 𝑅= 10 Ω, is connected across an AC source of 𝜋 𝜋 220 V, 50 Hz supply. The power factor of the circuit would be ____. o

Q28.When a dc voltage of 100 V is applied to an inductor, a dc current of 5 A flows through it. When an ac voltage of 200 V peak value is connected to inductor, its inductive reactance is found to be 20√3Ω. The power dissipated in the circuit is _______ W.

Q28.A alternating current at any instant is given by i = [6 + √56 sin(100πt + π/3)] A. The rms value of the current is ________ A.

Q29.The distance between object and its two times magnified real image as produced by a convex lens is 45 cm. The focal length of the lens used is ________ cm .

Q29.In a single slit experiment, a parallel beam of green light of wavelength 550 nm passes through a slit of width 0.20 mm. The transmitted light is collected on a screen 100 cm away. The distance of first order minima from the central maximum will be x × 10−5 m . The value of x is : JEE Main 2024 (05 Apr Shift 2) JEE Main Previous Year Paper

Q29.Two immiscible liquids of refractive indices 8 and 3 respectively are put in a beaker as shown in the figure. 5 2 The height of each column is 6 cm . A coin is placed at the bottom of the beaker. For near normal vision, the apparent depth of the coin is α 4 cm . The value of α is _______.

Q29.A parallel beam of monochromatic light of wavelength 600 nm passes through single slit of 0.4 mm width. Angular divergence corresponding to second order minima would be ______ ×10−3rad.

Q29.In a double slit experiment shown in figure, when light of wavelength 400 nm is used, dark fringe is observed at P . If D = 0. 2 m, the minimum distance between the slits S1 and S2 is α mm . Write the value of 10α to the nearest integer. JEE Main 2024 (29 Jan Shift 1) JEE Main Previous Year Paper

Q29.A light ray is incident on a glass slab of thickness 4√3 cm and refractive index √2 . The angle of incidence is equal to the critical angle for the glass slab with air. The lateral displacement of ray after passing through glass slab is _____ cm . ( Given sin 15∘= 0.25)

Q29.In a Young's double slit experiment, the intensity at a point is ( 14 )th of the maximum intensity, the minimum distance of the point from the central maximum is ________ μm . (Given : λ = 600 nm, d = 1.0 mm, D = 1.0 m )

Q29.In Young's double slit experiment, monochromatic light of wavelength 5000 A is used. The slits are 1 . 0 mm apart and screen is placed at 1 . 0 m away from slits. The distance from the centre of the screen where intensity becomes half of the maximum intensity for the first time is ______ × 10-6 m .

Q29.Light from a point source in air falls on a convex curved surface of radius 20 cm and refractive index 1 . 5. If the source is located at 100 cm from the convex surface, the image will be formed at ______ cm from the object. JEE Main 2024 (31 Jan Shift 2) JEE Main Previous Year Paper

Q29.The refractive index of prism is μ = √3 and the ratio of the angle of minimum deviation to the angle of prism is one. The value of angle of prism is _______.

Q29.A capacitor of reactance 4√3Ω and a resistor of resistance 4Ω are connected in series with an ac source of peak value 8√2 V . The power dissipation in the circuit is ________ W.

Q29.The distance between object and its 3 times magnified virtual image as produced by a convex lens is 20 cm . The focal length of the lens used is ________ cm .

Q29.In a single slit diffraction pattern, a light of wavelength 6000 A is used. The distance between the first and third minima in the diffraction pattern is found to be 3 mm when the screen is placed 50 cm away from slits. The width of the slit is ____ ×10−4 m .

Q29.Two wavelengths λ1 and λ2 are used in Young's double slit experiment. λ1 = 450 nm and λ2 = 650 nm. The minimum order of fringe produced by λ2 which overlaps with the fringe produced by λ1 is n. The value of n is _____.