Practice Questions

Q14.In a co-axial straight cable, the central conductor and the outer conductor carry equal currents in opposite directions. The magnetic field is zero : (1) outside the cable (2) inside the outer conductor (3) inside the inner conductor (4) in between the two conductors

Q14.The primary side of a transformer is connected to 230 V, 50 Hz supply. The turn ratio of primary to secondary winding is 10 : 1. Load resistance connected to the secondary side is 46 Ω. The power consumed in it is: (1) 12 . 5 W (2) 10 . 0 W (3) 11 . 5 W (4) 12 . 0 W

Q14.To measure the temperature coefficient of resistivity α of a semiconductor, an electrical arrangement shown in the figure is prepared. The arm BC is made up of the semiconductor. The experiment is being conducted at 25°C and resistance of the semiconductor arm is 3 m𝛺. Arm BC is cooled at a constant rate of 2 °C s-1. If the galvanometer G shows no deflection after 10 s, then α is: (1) -2 × 10-2 ∘C-1 (2) -1 . 5 × 10-2 ∘C-1 (3) -1 × 10-2 ∘C-1 (4) -2 . 5 × 10-2 ∘C-1

Q14.A series LR circuit connected with an ac source E = (25 sin 1000t) V has a power factor of 1 . If the source √2 of emf is changed to E = (20 sin 2000t) V, the new power factor of the circuit will be : (1) 1 (2) 1 √2 √3 (3) 1 (4) 1 √5 √7

Q14.Given below are two statements: Statement I: In an LCR series circuit, current is maximum at resonance. Statement II: Current in a purely resistive circuit can never be less than that in a series LCR circuit when connected to same voltage source. In the light of the above statements, choose the correct from the options given below: (1) Statement I is false but Statement II is true (2) Statement I is true but Statement II is false (3) Both Statement I and Statement II are true (4) Both Statement I and Statement II are false

Q14.In an a.c. circuit, voltage and current are given by: V = 100 sin(100t) V and I = 100 sin(100t + π3 ) mA respectively. The average power dissipated in one cycle is : (1) 5 W (2) 10 W (3) 2. 5 W (4) 25 W

Q14.An electron is projected with uniform velocity along the axis inside a current carrying long solenoid. Then : (1) the electron will continue to move with uniform (2) the electron will be accelerated along the axis. velocity along the axis of the solenoid. (3) the electron path will be circular about the axis. (4) the electron will experience a force at 45∘ to the axis and execute a helical path.

Q14. Match List I with List II Choose the correct answer from the options given below: (1) A-I. B-IV, C-II, D-III (2) A-IV. B-I. C-II. D-III (3) A-IV. B-I, C-III, D-II (4) A-I. B-IV, C-III, D-II

Q14.A coil of negligible resistance is connected in series with 90Ω resistor across 120 V, 60 Hz supply. A voltmeter reads 36 V across resistance. Inductance of the coil is : JEE Main 2024 (08 Apr Shift 2) JEE Main Previous Year Paper (1) 0.286H (2) 0.76H (3) 2.86H (4) 0.91H

Q14.Given below are two statements : Statement (I) : When currents vary with time, Newton's third law is valid only if momentum carried by the electromagnetic field is taken into account. Statement (II) : Ampere's circuital law does not depend on Biot-Savart's law. 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) Statement I is true but Statement II is false (3) Both Statement I and Statement II are false (4) Statement I is false but Statement II is true

Q14.A beam of unpolarised light of intensity 𝐼0 is passed through a polaroid 𝐴 and then through another polaroid 𝐵 which is oriented so that its principal plane makes an angle of 45° relative to that of 𝐴. The intensity of emergent light is : (1) 𝐼0 (2) 𝐼0 4 𝐼0 𝐼0 (3) (4) 2 8

Q15.UV light of 4.13eV is incident on a photosensitive metal surface having work function 3.13eV. The maximum kinetic energy of ejected photoelectrons will be: (1) 4.13eV (2) 3.13eV (3) 1eV (4) 7.26eV

Q15.A plane electromagnetic wave propagating in x-direction is described by Ey = (200 V m−1) sin[1. 5 × 107t −0. 05x]; The intensity of the wave is : (Use ϵ0 = 8. 85 × 10−12 C2 N−1 m−2 ) (1) 35. 4 W m−2 (2) 53. 1 W m−2 (3) 26. 6 W m−2 (4) 106. 2 W m−2

Q15. List-I List-II EM-Wave Wavelength Range (A) Infra-red (I) < 10−3 nm Match List-I with List-II : (B) Ultraviolet (II) 400 nm to 1 nm (C) X-rays S (III) 1 mm to 700 nm (D) Gamma rays (IV) 1 nm to 10−3 nm (1) (A)-(III), (B)-(II), (C)-(IV), (D)-(I) (2) (A)-(II), (B)-(I), (C)-(IV), (D)-(III) (3) (A)-(IV), (B)-(III), (C)-(II), (D)-(I) (4) (A)-(I), (B)-(III), (C)-(II), (D)-(IV)

Q15.In finding out refractive index of glass slab the following observations were made through travelling microscope 50 vernier scale division = 49MSD; 20 divisions on main scale in each cm For mark on paper JEE Main 2024 (06 Apr Shift 2) JEE Main Previous Year Paper MSR = 8.45 cm, VC = 26 For mark on paper seen through slab MSR = 7.12 cm, V C = 41 For powder particle on the top surface of the glass slab MSR = 4.05 cm, VC = 1 (MSR = Main Scale Reading, VC = Vernier Coincidence) Refractive index of the glass slab is : (1) 1.52 (2) 1.35 (3) 1.42 (4) 1.24

Q15.A coil is placed perpendicular to a magnetic field of 5000 T. When the field is changed to 3000 T in 2 s, an induced emf of 22 V is produced in the coil. If the diameter of the coil is 0 . 02 m, then the number of turns in the coil is: (1) 7 (2) 70 (3) 35 (4) 140

Q15.Critical angle of incidence for a pair of optical media is 45∘ . The refractive indices of first and second media are in the ratio: (1) 1 : √2 (2) √2 : 1 (3) 2 : 1 (4) 1 : 2

Q15.The position of the image formed by the combination of lenses is : (1) 15 cm (right of second lens) (2) 30 cm (left of third lens) (3) 15 cm (left of second lens) (4) 30 cm (right of third lens)

Q15.Given below are two statements: Statement I: Electromagnetic waves carry energy as they travel through space and this energy is equally shared by the electric and magnetic fields. Statement II: When electromagnetic waves strike a surface, a pressure is exerted on the surface. In the light of the above statements, choose the most appropriate answer from the options given below: (1) Statement I is incorrect but Statement II is (2) Both Statement I and Statement II are correct correct (3) Both Statement I and Statement II are incorrect (4) Statement I is correct but Statement II is incorrect

Q15.If the total energy transferred to a surface in time 𝑡 is 6 . 48 × 105 J, then the magnitude of the total momentum delivered to this surface for complete absorption will be : (1) 2 . 46 × 10-3 kg m s-1 (2) 2 . 16 × 10-3 kg m s-1 (3) 1 . 58 × 10-3 kg m s-1 (4) 4 . 32 × 10-3 kg m s-1

Q15.In series LCR circuit, the capacitance is changed from 𝐶 to 4𝐶. To keep the resonance frequency unchanged, the new inductance should be : 1 (1) reduced by 4𝐿 (2) increased by 2𝐿 (3) reduced by 3 (4) increased to 4𝐿 4𝐿 o

Q15.A plane EM wave is propagating along x direction. It has a wavelength of 4 mm . If electric field is in y direction with the maximum magnitude of 60Vm−1 , the equation for magnetic field is : (1) Bz = 2 × 10−7 sin [ π2 × 103 (x −3 × 108t)]^kT (2) Bz = 60 sin [ π2 (x −3 × 108t)]^kT (3) Bx = 60 sin [ π2 (x −3 × 108t)]i ^ T (4) Bz = 2 × 10−7 sin [ π2 (x −3 × 108t)]^kT JEE Main 2024 (09 Apr Shift 1) JEE Main Previous Year Paper

Q15.Two conducting circular loops A and B are placed in the same plane with their centers coinciding as shown in figure. The mutual inductance between them is : (1) μ0πb2 (2) μo ⋅b2a 2π 2a (3) μ0 2π ⋅a2b (4) μ0πa22b

Q15.A plane electromagnetic wave of frequency 35 MHz travels in free space along the X -direction. At a → particular point (in space and time) E = 9. 6ˆj V m−1 . The value of magnetic field at this point is: (1) 3. 2 × 10−8ˆk T (2) 3. 2 × 10−8ˆi (3) 9. 6ˆj T (4) 9. 6 × 10−8ˆk T

Q15.Primary coil of a transformer is connected to 220 V AC . Primary and secondary turns of the transforms are 100 and 10 respectively. Secondary coil of transformer is connected to two series resistances as shown in figure. The output voltage (V0) is : (1) 7 V (2) 15 V (3) 44 V (4) 22 V . The