Practice Questions

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.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.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.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.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.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.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.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.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 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.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.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.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 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.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.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.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.A microscope was initially placed in air (refractive index 1 ). It is then immersed in oil (refractive index 2 ). For a light whose wavelength in air is λ, calculate the change of microscope's resolving power due to oil and choose the correct option (1) Resolving power will be 1 in the oil than it was (2) Resolving power will be twice in the oil than it 4 in the air was in the air. (3) Resolving power will be four times in the oil than (4) Resolving power will be 1 in the oil than it was 2 it was in the air. in the air.

Q16.For a series LCR circuit, I vs ω curve is shown (a) To the left of ωr , the circuit is mainly capacitive. (b) To the left of ωr , the circuit is mainly inductive. (c) At ωr , impedance of the circuit is equal to the resistance of the circuit. (d) At ωr , impedance of the circuit is 0 . Choose the most appropriate answer from the options given below. (1) (a) and (d) only (2) (b) and (d) only (3) (a) and (c) only (4) (b) and (c) only

Q16.Match List - I with List - II JEE Main 2022 (27 Jun Shift 1) JEE Main Previous Year Paper List-I List-II (a) Ultravoilet rays (i) Study crystal structure (b) Microwaves (ii) Greenhouse effect (c) Infrared waves (iii) Sterilizing surgical instrument (d) X -rays (iv) Radar system (1) (a) −(iii), (b)(iv), (c) −(ii), (d) −(i) (2) (a) −(iii), (b)(i), (c) −(ii), (d) −(iv) (3) (a) −(iv), (b)(iii), (c) −(ii), (d) −(i) (4) (a) −(iii), (b)(iv), (c) −(i), (d) −(ii)

Q16.A light whose electric field vectors are completely removed by using a good polaroid, allowed to incident on the surface of the prism at Brewster's angle. Choose the most suitable option for the phenomenon related to the prism. (1) Reflected and refracted rays will be (2) Wave will propagate along the surface of prism. perpendicular to each other. (3) No refraction, and there will be total reflection of (4) No reflection. and there will be total transmission light. of light.

Q16.In normal adjustment, for a refracting telescope, the distance between objective and eye piece is 30 cm. The focal length of the objective, when the angular magnification of the telescope is 2, will be: (1) 20 cm (2) 30 cm (3) 10 cm (4) 15 cm 1 . 227

Q16.A proton, a deuteron and an α-particle with same kinetic energy enter into a uniform magnetic field at right angle to magnetic field. The ratio of the radii of their respective circular paths is : (1) 1 : √2 : √2 (2) 1 : √2 : 1 (3) √2 : 1 : 1 (4) None of these

Q16.A resistance of 40 Ω is connected to a source of alternating current rated 220 V, 50 Hz. Find the time taken by the current to change from its maximum value to the rms value : (1) 2. 5 ms (2) 1. 25 ms (3) 2. 5 s (4) 0. 25 s