Practice Questions

Q14.The equation of current in a purely inductive circuit is 5sin49𝜋𝑡- 30°. If the inductance is 30mH then the equation for the voltage across the inductor, will be (1) 1 . 47sin49𝜋𝑡- 30° (2) 1 . 47sin49𝜋𝑡+ 60° (3) 23 . 1sin49𝜋𝑡- 30° (4) 23 . 1sin49𝜋𝑡+ 60°

Q14.The electromagnetic waves travel in a medium at a speed of 2 . 0 × 108 m s-1. The relative permeability of the medium is 1 . 0. The relative permittivity of the medium will be (1) 2 . 25 (2) 4 . 25 (3) 6 . 25 (4) 8 . 25

Q14.What will be the most suitable combination of three resistors A = 2 Ω, B = 4 Ω, C = 6 Ω so that ( 223 )Ω is equivalent resistance of combination? (1) Parallel combination of A and C connected in series with B (2) Parallel combination of A and B connected in series with C (3) Series combination of A and C connected in parallel with B. (4) Series combination of B and C connected in parallel with A.

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.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.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.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.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.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.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.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 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 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.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.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 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 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 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

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.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.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.Two coherent sources of light interfere. The intensity ratio of two sources is 1 : 4. For this interference pattern if the value of Imax+Imin is equal to 2α+1 , then α will be Imax−Imin β+3 β (1) 1. 5 (2) 2 (3) 0. 5 (4) 1

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

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