Practice Questions

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.Given below are two statements : Statement I: A time varying electric field is a source of changing magnetic field and vice-versa. Thus a disturbance in electric or magnetic field creates EM waves. Statement II: In a material medium, the EM wave travels with speed v = 1 . √μ0ϵ0 JEE Main 2022 (27 Jun Shift 2) JEE Main Previous Year Paper In the light of the above statements, choose the correct answer from the options given below. (1) Both statement I and statement II are true (2) Both statement I and statement II are false (3) Statement I is correct but statement II is false (4) Statement I is incorrect but statement II is true

Q16.Given below are two statements : Statement I: The electric force changes the speed of the charged particle and hence changes its kinetic energy; whereas the magnetic force does not change the kinetic energy of the charged particle. Statement II: The electric force accelerates the positively charged particle perpendicular to the direction of electric field. The magnetic force accelerates the moving charged particle along the direction of magnetic field. In the light of the above statements, choose the most appropriate answer from the options given below : (1) Both Statement I and Statement II are correct. (2) Both Statement I and Statement II are incorrect. (3) Statement I is correct but Statement II is (4) Statement I is incorrect but Statement II is incorrect. correct.

Q16.Which of the following statement is correct? (1) In primary rainbow, observer sees red colour on (2) In primary rainbow, observer sees violet colour the top and violet on the bottom on the top and red on the bottom (3) In primary rainbow, light wave suffers total (4) Primary rainbow is less bright than secondary internal reflection twice before coming out of rainbow. water drops

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.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.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 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.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 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.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.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.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.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.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.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.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.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

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.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.A parallel beam of light of wavelength 900 nm and intensity 100 Wm−2 is incident on a surface perpendicular to the beam. The number of photons crossing 1 cm2 area perpendicular to the beam in one second is (1) 3 × 1016 (2) 4. 5 × 1016 (3) 4. 5 × 1017 (4) 4. 5 × 1020

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.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.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