Practice Questions

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.A straight magnetic strip has a magnetic moment of 44Am2 . If the strip is bent in a semicircular shape, its magnetic moment will be _______ Am2 . (given π = 227 )

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.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.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.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.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 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.For a given series LCR circuit it is found that maximum current is drawn when value of variable capacitance is 25nF. If resistance of 200Ω and 100mH inductor is being used in the given circuit. The frequency of ac source is ______ ×103 Hz . (given π2 = 10 )

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.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.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 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 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.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.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.A power transmission line feeds input power at 2 . 3 kV to a step down transformer with its primary winding having 3000 turns. The output power is delivered at 230 V by the transformer. The current in the primary of the transformer is 5 A and its efficiency is 90%. The winding of transformer is made of copper. The output current of transformer is ____A.

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.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.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.Two waves of intensity ratio 1 : 9 cross each other at a point. The resultant intensities at the point, when (a) 𝐼1 10 Waves are incoherent is 𝐼1 𝑏 Waves are coherent is 𝐼2 and differ in phase by 60o. If = 𝑥, then 𝑥= 𝐼2 _________. JEE Main 2024 (31 Jan Shift 1) JEE Main Previous Year Paper

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 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.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 .