Practice Questions

Q16.The two light beams having intensities 𝐼 and 9𝐼 interfere to produce a fringe pattern on a screen. The phase 𝜋 difference between the beams is at point 𝑃 and 𝜋 at point 𝑄. Then the difference between the resultant 2 intensities at 𝑃 and 𝑄 will be : (1) 2𝐼 (2) 6𝐼 (3) 5𝐼 (4) 7𝐼

Q16.The kinetic energy of emitted electron is E when the light incident on the metal has wavelength λ . To double the kinetic energy, the incident light must have wavelength: (1) hc (2) hcλ Eλ−hc Eλ+hc (3) hλ (4) hcλ Eλ+hc Eλ−hc

Q16.In young's double slit experiment performed using a monochromatic light of wavelength λ , when a glass plate (μ = 1. 5) of thickness xλ is introduced in the path of the one of the interfering beams, the intensity at the position where the central maximum occurred previously remains unchanged. The value of x will be (1) 3 (2) 2 (3) 1. 5 (4) 0. 5

Q16.Light wave travelling in air along x-direction is given by Ey = 540 sin π × 104(x −ct) V m−1 . Then, the peak value of magnetic field of wave will be (Given c = 3 × 108 m s−1 ) (1) 18 × 10−7 T (2) 54 × 10−7 T (3) 54 × 10−8 T (4) 18 × 10−8 T

Q16.Light travels in two media 𝑀1 and 𝑀2 with speeds 1 . 5 × 108 m s-1 and 2 . 0 × 108 m s-1 respectively. The critical angle between them is 3 (1) tan-1 (2) tan-12 √7 3 (3) cos-13 (4) sin-12 4 3

Q16.The Q-value of a nuclear reaction and kinetic energy of the projectile particle, Kp are related as (1) Q = Kp (2) (Kp + Q) < 0 (3) Q < Kp (4) (Kp + Q) > 0

Q16.The power of a lens (biconvex) is 1. 25 m−1 in particular medium. Refractive index of the lens is 1. 5 and radii of curvature are 20 cm and 40 cm respectively. The refractive index of surrounding medium: JEE Main 2022 (28 Jul Shift 2) JEE Main Previous Year Paper (1) 1. 0 (2) 97 (3) 3 (4) 4 2 3

Q16.A metallic conductor of length 1 m rotates in a vertical plane parallel to east-west direction about one of its end with angular velocity 5 rad s−1 . If the horizontal component of earth's magnetic field is 0. 2 × 10−4 T, then emf induced between the two ends of the conductor is (1) 5μV (2) 50μV (3) 5 mV (4) 50 mV

Q16.A wave of frequency = 3 GHz , strikes a particle of size ( 1001 ) th of (1) Diffraction (2) Scattering (3) Reflection (4) Refraction

Q16.In young's double slit experiment, the fringe width is 12 mm. If the entire arrangement is placed in water of refractive index 4 , then the fringe width becomes (in mm) 3 (1) 16 (2) 9 (3) 48 (4) 12

Q17.A nucleus of mass 𝑀 at rest splits into two parts having masses 𝑀' and 2𝑀' 𝑀' < 𝑀. The ratio of de Broglie 3 3 wavelength of two parts will be (1) 1: 2 (2) 2: 1 (3) 1: 1 (4) 2: 3

Q17.Two streams of photons, possessing energies to five and ten times the work function of metal are incident on the metal surface successively. The ratio of the maximum velocities of the photoelectron emitted, in the two cases respectively, will be (1) 1 : 2 (2) 1 : 3 (3) 2 : 3 (4) 3 : 2

Q17.In the following circuit, the correct relation between output (Y ) and inputs A and B will be JEE Main 2022 (28 Jun Shift 1) JEE Main Previous Year Paper (1) Y = A ⋅B (2) Y = A + B (3) Y = A ⋅B (4) Y = A + B

Q17.Find the ratio of energies of photons produced due to transition of an election of hydrogen atom from its(i) second permitted energy level to the first level, and (ii) the highest permitted energy level to the first permitted level. (1) 3 : 4 (2) 4 : 3 (3) 1 : 4 (4) 4 : 1

Q17.The speed of light in media ′A′ and ′B′ are 2. 0 × 1010 cm s−1 and 1. 5 × 1010 cm s−1 respectively. A ray of light enters from the medium B to A at an incident angle ′θ′. If the ray suffers total internal reflection, then (1) θ = sin−1( 34 ) (2) θ > sin−1( 32 ) (3) θ > sin−1( 34 ) (4) θ < sin−1( 43 )

Q17.For an object placed at a distance 2. 4 m from a lens, a sharp focused image is observed on a screen placed at a distance 12 cm from the lens. A glass plate of refractive index 1. 5 and thickness 1 cm is introduced between lens and screen such that the glass plate plane faces parallel to the screen. By what distance should the object be shifted so that a sharp focused image is observed again on the screen? (1) 0. 8 m (2) 3. 2 m (3) 1. 2 m (4) 5. 6 m

Q17.Let K1 and K2 be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength λ1 and λ2 , respectively are incident on a metallic surface. If λ1 = 3λ2 then : (1) K1 > K23 (2) K1 < K23 (3) K1 = K23 (4) K2 = K13

Q17.A plane electromagnetic wave travels in a medium of relative permeability 1. 61 and relative permittivity 6. 44 . If magnitude of magnetic intensity is 4. 5 × 10−2 A m−1 at a point, what will be the approximate magnitude of electric field intensity at that point ? (Given : Permeability of free space μ0 = 4π × 10−7 N A−2 , speed of light in vacuum c = 3 × 108 m s−1 ) (1) 16. 96 V m−1 (2) 2. 25 × 10−2 V m−1 (3) 8. 48 V m−1 (4) 6. 75 × 106 V m−1

Q17.The equation 𝜆= nm can be used to find the de-Broglie wavelength of an electron. In this equation 𝑥 x stands for : Where, 𝑚= mass of electron 𝑃= momentum of electron 𝐾= Kinetic energy of electron 𝑉= Accelerating potential in volts for electron (1) √𝑚𝐾 (2) √𝑃 (3) √𝐾 (4) √𝑉

Q17.A convex lens has power P . It is cut into two halves along its principal axis. Further one piece (out of the two halves) is cut into two halves perpendicular to the principal axis (as shown in figures). Choose the incorrect option for the reported pieces. (1) Power of L1 = P2 (2) Power of L2 = P2 (3) Power of L3 = P2 (4) Power of L1 = P

Q17.Light enters from air into a given medium at an angle of 45° with interface of the air-medium surface. After refraction, the light ray is deviated through an angle of 15° from its original direction. The refractive index of the medium is : (1) 1 . 732 (2) 1 . 333 (3) 1 . 414 (4) 2 . 732

Q17.A proton, a neutron, an electron and an 𝛼-particle have same energy. If 𝜆𝑝, 𝜆𝑛, 𝜆𝑒 and 𝜆𝛼 are the de Broglie's wavelengths of proton, neutron, electron and 𝛼 particle respectively, then choose the correct relation from the following (1) 𝜆𝑝= 𝜆𝑛> 𝜆𝑒> 𝜆𝛼 (2) 𝜆𝑎< 𝜆𝑛< 𝜆𝑝< 𝜆𝑒 (3) 𝜆𝑒< 𝜆𝑝= 𝜆𝑛> 𝜆𝛼 (4) 𝜆𝑒= 𝜆𝑝= 𝜆𝑛= 𝜆𝛼. 𝑅

Q17.Consider a light ray travelling in air is incident into a medium of refractive index √2n. The incident angle is twice that of refracting angle. Then, the angle of incidence will be (1) sin−1 √n (2) cos−1( √2n ) (3) sin−1(√2n) (4) 2 cos−1(√n2 )

Q17.With reference to the observations in photo-electric effect, identify the correct statements from below: A. The square of maximum velocity of photoelectrons varies linearly with frequency of incident light. B. The value of saturation current increases on moving the source of light away from the metal surface. C. The maximum kinetic energy of photo-electrons decreases on decreasing the power of LED (light emitting diode) source of light. D. The immediate emission of photo-electrons out of metal surface can not be explained by particle nature of light/electromagnetic waves. E. Existence of threshold wavelength can not be explained by wave nature of light/electromagnetic waves. Choose the correct answer from the options given below: (1) A and B only (2) A and E only (3) C and E only (4) D and E only

Q17.Using Young's double slit experiment, a monochromatic light of wavelength 5000Å produces fringes of fringe width 0. 5 mm. If another monochromatic light of wavelength 6000Å is used and the separation between the slits is doubled, then the new fringe width will be (1) 0. 5 mm (2) 1. 0 mm (3) 0. 6 mm (4) 0. 3 mm