Practice Questions

Q15.The deflection in moving coil galvanometer falls from 25 divisions to 5 division when a shunt of 24 Ω is applied. The resistance of galvanometer coil will be: (1) 12 Ω (2) 96 Ω (3) 48 Ω (4) 100 Ω

Q15.Electromagnetic waves travel in a medium with speed of 1.5 × 108 m s−1 . The relative permeability of the medium is 2.0 . The relative permittivity will be: (1) 2 (2) 4 (3) 5 (4) 1

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 an ac circuit, the instantaneous current is zero, when the instantaneous voltage is maximum. In this case, the source may be connected to : A. pure inductor. B. pure capacitor. C. pure resistor. D. combination of an inductor and capacitor. Choose the correct answer from the options given below : (1) A, B and C only (2) A and B only (3) B, C and D only (4) A, B and D only →

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

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

Q16.A hydrogen atom in ground state is given an energy of 10.2eV. How many spectral lines will be emitted due to transition of electrons? (1) 6 (2) 3 (3) 10 (4) 1

Q16.Given below are two statements : Statement (I) : When an object is placed at the centre of curvature of a concave lens, image is formed at the centre of curvature of the lens on the other side. Statement (II) : Concave lens always forms a virtual and erect image. 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 true but Statement II is false (4) Statement I is false but Statement II is true

Q16.The electric field in an electromagnetic wave is given by E = ^i40 cos ω(t −z/c)NC−1 . The magnetic field induction of this wave is (in SI unit) : (1) → →B = ^j40 cos ω(t −z/c) B = ^k 40C cos ω(t −z/c) (2) (3) → 40 (4) → 40 B = ^i C cos ω(t −z/c) B = ^j C cos ω(t −z/c)

Q16.A convex mirror of radius of curvature 30 cm forms an image that is half the size of the object. The object distance is : (1) −45 cm (2) 45 cm (3) −15 cm (4) 15 cm

Q16.If frequency of electromagnetic wave is 60 MHz and it travels in air along z direction then the corresponding electric and magnetic field vectors will be mutually perpendicular to each other and the wavelength of the wave in m is : (1) 2 . 5 (2) 10 (3) 5 (4) 2

Q16.In a plane EM wave, the electric field oscillates sinusoidally at a frequency of 5 × 1010 Hz and an amplitude of 50 V m – 1. The total average energy density of the electromagnetic field of the wave is : [Use 𝜀0 = 8 . 85 × 10 – 12 C2 N-1 m-2] (1) 1 . 106 × 10 – 8 J m – 3 (2) 4 . 425 × 10 – 8 J m – 3 (3) 2 . 212 × 10 – 8 J m – 3 (4) 2 . 212 × 10 – 10 J m – 3 𝐴

Q16.If the refractive index of the material of a prism is cot( A2 ), where A is the angle of prism then the angle of minimum deviation will be (1) π −2 A (2) π2 −2 A (3) π −A (4) π2 −A JEE Main 2024 (27 Jan Shift 1) JEE Main Previous Year Paper

Q16.A monochromatic light of wavelength 6000 A is incident on the single slit of width 0 . 01 mm. If the diffraction pattern is formed at the focus of the convex lens of focal length 20 cm, the linear width of the central maximum is : (1) 60 mm (2) 24 mm (3) 120 mm (4) 12 mm

Q16.For the thin convex lens, the radii of curvature are at 15 cm and 30 cm respectively. The focal length the lens is 20 cm. The refractive index of the material is : (1) 1.2 (2) 1.8 (3) 1.5 (4) 1.4

Q16.The width of one of the two slits in a Young's double slit experiment is 4 times that of the other slit. The ratio of the maximum of the minimum intensity in the interference pattern is: (1) 1 : 1 (2) 4 : 1 (3) 9 : 1 (4) 16 : 1

Q16.An alternating voltage of amplitude 40 V and frequency 4kHz is applied directly across the capacitor of 12μF. The maximum displacement current between the plates of the capacitor is nearly : (1) 10 A (2) 12 A (3) 8 A (4) 13 A

Q16.When a polaroid sheet is rotated between two crossed polaroids then the transmitted light intensity will be maximum for a rotation of : (1) 60° (2) 30° (3) 90° (4) 45°

Q16.If the distance between object and its two times magnified virtual image produced by a curved mirror is 15 cm , the focal length of the mirror must be : (1) 15 cm (2) −12 cm (3) −10 cm (4) 103 cm

Q16.A proton and an electron are associated with same de-Broglie wavelength. The ratio of their kinetic energies is: (Assume h=6.63 ×10−34 J s, me = 9.0 × 10−31 kg and mp = 1836 times me ) (1) 1 : √1836 (2) 1 : 18361 (3) 1 : 1 (4) 1: 1836 √1836

Q17.A convex lens of focal length 40 cm forms an image of an extended source of light on a photoelectric cell. A current I is produced. The lens is replaced by another convex lens having the same diameter but focal length 20 cm. The photoelectric current now is (1) I (2) 4I 2 (3) 2I (4) I

Q17.The diffraction pattern of a light of wavelength 400 nm diffracting from a slit of width 0. 2 mm is focused on the focal plane of a convex lens of focal length 100 cm. The width of the 1st secondary maxima will be : (1) 2 mm (2) 2 cm (3) 0. 02 mm (4) 0. 2 mm

Q17.In Young's double slit experiment, light from two identical sources are superimposing on a screen. The path difference between the two lights reaching at a point on the screen is 7λ . The ratio of intensity of fringe at this 4 point with respect to the maximum intensity of the fringe is: (1) 1 (2) 3 2 4 (3) 1 (4) 1 3 4

Q17.An electron revolving in 𝑛th Bohr orbit has magnetic moment 𝜇𝑛. If 𝜇𝑛 ∝ 𝑛𝑥, the value of 𝑥 is: (1) 2 (2) 1 (3) 3 (4) 0

Q17.The refractive index of a prism with apex angle 𝐴 is 𝑐𝑜𝑡 2. The angle of minimum deviation is : (1) 𝛿𝑚= 180° - 𝐴 (2) 𝛿𝑚= 180° - 3𝐴 (3) 𝛿𝑚= 180° - 4𝐴 (4) 𝛿𝑚= 180° - 2𝐴