Practice Questions

Q15.As shown in the figure, after passing through the medium 1. The speed of light 𝑣2 in medium 2 will be : (Given 𝑐= 3 × 108 m s-1 ) (1) 1 . 0 × 108 m s-1 (2) 0 . 5 × 108 m s-1 (3) 1 . 5 × 108 m s-1 (4) 3 . 0 × 108 m s-1

Q15.Match List - I with List - II List-I List-II (a) UV rays (i) Diagnostic tool in medicine (b) X -rays (ii) Water purification (c) Microwave (iii) Communication, Radar (d) Infrared wave (iv) Improving visibility in foggy days Choose the correct answer from the options given below : (1) (a) −(iii), (b) −(ii), (c) −(i), (d) −(iv) (2) (a) −(ii), (b) −(i), (c) −(iii), (d) −(iv) (3) (a) −(ii), (b) −(iv), (c) −(iii), (d) −(i) (4) (a) −(iii), (b) −(i), (c) −(ii), (d) −(iv)

Q15.The oscillating magnetic field in a plane electromagnetic wave is given by 𝐵𝑦= 5 × 10-6sin1000𝜋5𝑥- 4 × 108𝑡 T. The amplitude of electric field will be (1) 15 × 102Vm-1 (2) 5 × 10-6Vm-1 (3) 16 × 1012Vm-1 (4) 4 × 102Vm-1

Q15.The RMS value of conduction current in a parallel plate capacitor is 6 . 9 𝜇A. The capacity of this capacitor, if it is connected to 230 V AC supply with an angular frequency of 600 rad s-1, will be (1) 5pF (2) 50pF (3) 100pF (4) 200pF

Q15.The interference pattern is obtained with two coherent light sources of intensity ratio 4: 1. And the ratio 𝐼max + 𝐼min is 5 Then, the value of 𝑥 will be equal to : 𝐼max - 𝐼min 𝑥. (1) 3 (2) 4 (3) 2 (4) 1

Q15.Two long current carrying conductors are placed parallel to each other at a distance of 8 cm between them. The magnitude of magnetic field produced at mid-point between the two conductors due to current flowing in JEE Main 2022 (29 Jun Shift 2) JEE Main Previous Year Paper them is 300 μT. The equal current flowing in the two conductors is : (1) 30 A in the same direction. (2) 60 A in the opposite direction. (3) 30 A in the opposite direction. (4) 300 A in the opposite direction.

Q15.Identify the correct statements from the following descriptions of various properties of electromagnetic waves. A. In a plane electromagnetic wave electric field and magnetic field must be perpendicular to each other and direction of propagation of wave should be along electric field or magnetic field. B. The energy in electromagnetic wave is divided equally between electric and magnetic fields. C. Both electric field and magnetic field are parallel to each other and perpendicular to the direction of propagation of wave. D. The electric field, magnetic field and direction of propagation of wave must be perpendicular to each other. E. The ratio of amplitude of magnetic field to the amplitude of electric field is equal to speed of light. Choose the most appropriate answer from the options given below: (1) D only (2) B and D only (3) B, C and E only (4) A, B and E only

Q15.The current flowing through an ac circuit is given by I = 5 sin(120πt) A. How long will the current take to reach the peak value starting from zero? (1) 1 s (2) 60 s 60 (3) 120 1 s (4) 2401 s

Q15.A wire 𝑋 of length 50 cm carrying a current of 2 A is placed parallel to a long wire 𝑌 of length 5 m. The wire 𝑌 carries a current of 3 A. The distance between two wires is 5 cm and currents flow in the same direction. The force acting on the wire 𝑌 is : ​ (1) 1 . 2 × 10-5 N directed towards wire 𝑋. (2) 1 . 2 × 10-4 N directed away from wire 𝑋. (3) 1 . 2 × 10-4 N directed towards wire 𝑋. (4) 2 . 4 × 10-5 N directed towards wire 𝑋.

Q15.Sun light falls normally on a surface of area 36 cm2 and exerts an average force of 7. 2 × 10−9 N within a time period of 20 minutes. Considering a case of complete absorption, the energy flux of incident light is (1) 25. 92 × 102 W cm−2 (2) 8. 64 × 10−6 W cm−2 (3) 6. 0 W cm−2 (4) 0. 06 W cm−2

Q15.A charge particle moves along circular path in a uniform magnetic field in a cyclotron. The kinetic energy of the charge particle increases to 4 times its initial value. What will be the ratio of new radius to the original radius of circular path of the charge particle? (1) 1 : 1 (2) 1 : 2 (3) 2 : 1 (4) 1 : 4

Q15.Two long parallel conductors S1 and S2 are separated by a distance 10 cm and carrying currents of 4 A and 2 A respectively. The conductors are placed along x-axis in X −Y plane. There is a point P located between the conductors (as shown in figure). + m s−1 ; where ˆi & A charge particle of 3π coulomb is passing through the point P with velocity →v= (2ˆi 3ˆj) ˆj represents unit vector along x & yaxis respectively. The force acting on the charge particle is 4π × + N. The value of x is 10−5(−xˆi 2ˆj) (1) 2 (2) 1 (3) 3 (4) −3

Q15.The difference of speed of light in the two media 𝐴 and 𝐵𝑣𝐴- 𝑣𝐵 is 2 . 6 × 107 m s-1. If the refractive index of medium 𝐵 is 1 . 47, then the ratio of refractive index of medium 𝐵 to medium 𝐴 is: (Given : speed of light in vacuum 𝑐= 3 × 108 m s-1) (1) 1 . 303 (2) 1 . 318 (3) 1 . 13 (4) 0 . 12

Q15.A beam of light travelling along X -axis is described by the electric field Ey = 900 sin ω(t −xc ). The ratio of electric force to magnetic force on a charge q moving along Y -axis with a speed of 3 × 107 m s−1 will be : [Given speed of light = 3 × 108 m s−1 ] (1) 1 : 1 (2) 1 : 10 (3) 10 : 1 (4) 1 : 2

Q15.The de Broglie wavelengths for an electron and a photon are λe and λp respectively. For the same kinetic energy of electron and photon, which of the following presents the correct relation between the de Broglie wavelengths of two? (1) λp ∝λ2e (2) λp ∝λe (3) λp ∝√λe (4) λp ∝√1λe

Q15.The soft-iron is a suitable material for making an electromagnet. This is because soft-iron has (1) low coercivity and high retentivity. (2) low coercivity and low permeability. (3) high permeability and low retentivity. (4) high permeability and high retentivity.

Q15.When you walk through a metal detector carrying a metal object in your pocket, it raises an alarm. This phenomenon works on (1) Electromagnetic induction (2) Resonance in ac circuits (3) Mutual induction in ac circuits (4) interference of electromagnetic waves

Q15.The magnetic field of a plane electromagnetic wave is given by → B = 2 × 10−8 sin(0. 5 × 103x + 1. 5 × 1011t)ˆj T. The amplitude of the electric field would be (1) 6 Vm−1 along x-axis (2) 3 Vm−1 along z-axis (3) 6 Vm−1 along z-axis (4) 2 × 10−8 Vm−1 along z-axis

Q15.The magnetic field at the centre of a circular coil of radius r, due to current I flowing through it, is B. The magnetic field at a point along the axis at a distance r from the centre is : 2 (1) B (2) 2B 2 (3) 2 3 (4) 2 3 B B ( √5 ) ( √3 )

Q15.An EM wave propagating in x-direction has a wavelength of 8 mm. The electric field vibrating y-direction has maximum magnitude of 60 Vm−1 . Choose the correct equations for electric and magnetic fields if the EM wave is propagating in vacuum : j V m−1 (1) Ey = 60 sin[ π4 × 103(x −3 × 108t)]ˆj V m−1 (2) Ey = 60 sin[ π4 × 103(x −3 × 108t)]ˆ Bz = 2 sin[ π4 × 103(x −3 × 108t)]ˆk T Bz = 2 × 10−7 sin[ π4 × 103(x −3 × 108t)]ˆk T (3) Ey = 2 × 10−7 sin[ π4 × 103(x −3 × 108t)]ˆj V m−1(4) Ey = 2 × 10−7 sin[ π4 × 104(x −4 × 108t)]ˆj V m−1 Bz = 60 sin[ π4 × 103(x −3 × 108t)]ˆk T Bz = 60 sin[ π4 × 104(x −4 × 108t)]ˆk T

Q15.Two coils of self inductance L1 and L2 are connected in series combination having mutual inductance of the coils as M . The equivalent self inductance of the combination will be (1) 1 + 1 + M1 (2) L1 + L2 −2M L1 L2 (3) L1 + L2 + M (4) L1 + L2 + 2M JEE Main 2022 (26 Jun Shift 2) JEE Main Previous Year Paper

Q15.If Electric field intensity of a uniform plane electro magnetic wave is given as E = −301. 6 sin(kz −ωt)ˆax + 452. 4 sin(kz −ωt)ˆay V m−1. Then, magnetic intensity H of this wave in A m−1 will be [Given : Speed of light in vacuum c = 3 × 108 m s−1 , Permeability of vacuum μ0 = 4π × 10−7 N A−2 ] (1) +0. 8 sin(kz −ωt)ˆay + 0. 8 sin(kz −ωt)ˆax (2) +1. 0 × 10−6 sin(kz −ωt)ˆay + 1. 5 × 10−6(kz −ωt)ˆax (3) −0. 8 sin(kz −ωt)ˆay −1. 2 sin(kz −ωt)ˆax (4) −1. 0 × 10−6 sin(kz −ωt)ˆay −1. 5 × 10−6 sin(kz −ωt)ˆa λ, then this phenomenon is called as

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.A circuit element 𝑋 when connected to an AC supply of peak voltage 100 V gives a peak current of 5 A which is in phase with the voltage. A second element 𝑌 when connected to the same AC supply also gives the 𝜋 same value of peak current which lags behind the voltage by 2. If 𝑋 and 𝑌 are connected in series to the same supply, what will be the rms value of the current in ampere? (1) 10 (2) 5 √2 √2 5 (3) 5√2 (4) 2

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