Practice Questions

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 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.A transformer has an efficiency of 80% and works at 10 V and 4 kW . If the secondary voltage is 240 V, then the current in the secondary coil is: (1) 1 . 59 A (2) 13 . 33 A (3) 1 . 33 A (4) 15 . 1 A

Q15.An object is placed in a medium of refractive index 3. An electromagnetic wave of intensity 6 × 108 W m-2 falls normally on the object and it is absorbed completely. The radiation pressure on the object would be (speed of light in free space = 3 × 108 m s-1 ): (1) 36 N m-2 (2) 18 N m-2 (3) 6 N m-2 (4) 2 N m-2

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.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.Arrange the following in the ascending order of wavelength: A. Gamma rays (λ1) B. x - rays (λ2) C. Infrared waves (λ3) D. Microwaves (λ4) Choose the most appropriate answer from the options given below (1) λ4 < λ3 < λ1 < λ2 (2) λ2 < λ1 < λ4 < λ3 (3) λ1 < λ2 < λ3 < λ4 (4) λ4 < λ3 < λ2 < λ1

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.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.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.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 →

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.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 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.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.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.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 proton and an electron have the same de Broglie wavelength. If Kp and Ke be the kinetic energies of proton and electron respectively, then choose the correct relation : (1) Kp > Ke (2) Kp < Ke (3) Kp = Ke (4) Kp = Ke2

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.When unpolarized light is incident at an angle of 60° on a transparent medium from air. The reflected ray is completely polarized. The angle of refraction in the medium is (1) 30° (2) 60° (3) 90° (4) 45°

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.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.The electric field of an electromagnetic wave in free space is represented as →E = E0 cos(ωt −kz)ˆi corresponding magnetic induction vector will be : (1) → (2) → E0 B = E0C B = C cos(ωt −kz)ˆj cos(ωt −kz)ˆj (3) → (4) → E0 B = E0C + B = C + cos(ωt kz)ˆj cos(ωt kz)ˆj JEE Main 2024 (30 Jan Shift 1) JEE Main Previous Year Paper