Practice Questions

Q29.A parallel beam of monochromatic light of wavelength 5000 A is incident normally on a single narrow slit of width 0 . 001 mm. The light is focused by convex lens on screen, placed on its focal plane. The first minima will be formed for the angle of diffraction of ______ (degree). 𝛼

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.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 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 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.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.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.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.Two slits are 1 mm apart and the screen is located 1 m away from the slits. A light of wavelength 500 nm is used. The width of each slit to obtain 10 maxima of the double slit pattern within the central maximum of the JEE Main 2024 (08 Apr Shift 2) JEE Main Previous Year Paper single slit pattern is _____ ×10−4 m

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.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.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.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.Two coherent monochromatic light beams of intensities I and 4I are superimposed. The difference between maximum and minimum possible intensities in the resulting beam is xI . The value of x 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.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 _____.

Q29.In Young's double slit experiment, carried out with light of wavelength 5000\AA, the distance between the slits is 0.3 mm and the screen is at 200 cm from the slits. The central maximum is at x = 0 cm . The value of x for third maxima is _____ mm .

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.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 .

Q30.If three helium nuclei combine to form a carbon nucleus then the energy released in this reaction is _____ ×10−2MeV . (Given 1u = 931MeV/c2 , atomic mass of helium = 4.002603u )

Q30.In an alpha particle scattering experiment distance of closest approach for the α particle is 4.5 × 10−14 m . If target nucleus has atomic number 80 , then maximum velocity of α - particle is _______ ×105 m/s approximately. = 9 × 109 SI unit, mass of α particle = 6.72 × 10−27 kg) ( 4πϵ01

Q30.The radius of a nucleus of mass number 64 is 4 . 8 fermi. Then the mass number of another nucleus having radius of 4 fermi is 1000 where 𝑥 is _________. 𝑥,

Q30.A potential divider circuit is connected with a dc source of 20 V, a light emitting diode of glow in voltage 1.8 V and a zener diode of breakdown voltage of 3.2 V. The length (PR) of the resistive wire is 20 cm. The minimum length of PQ to just glow the LED is _____ cm

Q30.The disintegration energy Q for the nuclear fission of 235U →140Ce + 94Zr + n is ______ MeV . Given atomic masses of 235U : 235.0439u; 140Ce : 139.9054u, 94Zr : 93.9063u; n : 1.0086u, Value of c2 = 931MeV/u

Q30.When a hydrogen atom going from n = 2 to n = 1 emits a photon, its recoil speed is x5 m s−1 . Where x = _______. (Use: mass of hydrogen atom = 1. 6 × 10−27 kg , charge of electron e = 1. 6 × 10−19 C)