Electromagnetic Waves JEE Main Questions 2025: Important Practice Questions with PYQs
Electromagnetic Waves chapter holds 6% of questions in the JEE Main Physics exam 2025. Candidates must check the important questions, along with previous year's questions, and practice questions to ensure the best preparation for the JEE Main 2025 exam in the article
Electromagnetic Waves JEE Main Questions 2025: Candidates preparing for the JEE Main 2025 exam must go through the Electromagnetic Waves chapter in-depth as it is one of the most important chapters in the JEE main physics syllabus 2025, as it holds up to 6% of questions in form of numerical and direct question based on theories. Aspirants appearing for JEE Main 2025 exam can expect 2 to 3 questions on this topic. We have compiled the list of important practice questions, previous year's questions, and more related to the Electromagnetic waves for JEE Main 2025. Practice the questions provided to check the understanding and preparation level for the exam.
JEE Main 2025 Electromagnetic Waves Important Questions
Candidates can check important practice questions related to electromagnetic waves for the JEE main exam 2025 in the table below:
Important Practice Questions From Electromagnetic Waves for JEE Main 2025 | |||||||||||
Questions | Solution | ||||||||||
Q: A plane electromagnetic wave travels in free space along the x-direction. The electric field component of the wave at a particular point of space and time is E = 6 V m–1 along the y-direction. Its corresponding magnetic field component, B would be
| The direction of electromagnetic wave travelling is given by K- = E- X B- As the wave travels along the x-direction and E along the y-direction, So, B must point towards the z-direction. The magnetic field, B = E/c = 6/(3 x 108) = 2 x 10-8 T | ||||||||||
Q: A red LED emits light at 0.1 watts uniformly around it. The amplitude of the electric field of the light at a distance of 1 m from the diode is
| The intensity of light, I = uav c Also, I = P/4pi r2 and uav = 1/2 e0E02 ∴ P/4pi r2 = (½)ε0E02c Here, P = 0.1 W, r = 1 m, c = 3 × 108 m s–1 1/4pi E0 = 9 x 109 N C–2 m2 E0=2 X 0.1 X 9 X 10912 X 3 X 108=6 = 2.45 V m-1 | ||||||||||
Q: The mean intensity of radiation on the surface of the Sun is about 108 W/m2. The RMS value of the corresponding magnetic field is closest to
| Mean intensity I= (B2rms/u0)c B2rms = (108 x 4pix 10-7)/(3 x 108) Brms ≈ 10-4 T | ||||||||||
Q: 50 W/m2 energy density of sunlight is normally incident on the surface of a solar panel. Some part of incident energy (25%) is reflected from the surface and the rest is absorbed. The force exerted on 1m2 surface area will be close to (c = 3 × 108 m/s)
| Given energy density = 50 W/m2 Here, change in momentum delta p = pf - pi delta p = (-pi /4) – pi delta p = -5pi /4, since pi = E/c = 50 W/s/(3 x 108) delta p/delta t = F = |-5pi/4丨= (5/4) x (50/(3 x 108) = 20.8 x 10-8 N ≈ 20x 10-8 N | ||||||||||
Q: Match List-I (Electromagnetic wave type) with List-II (Its association/application) and select the correct option from the choices given below the lists
P Q R S (a) (i) (ii) (iii) (iv) (b) (iv) (iii) (ii) (i) (c) (i) (ii) (iv) (iii) (d) (iii) (ii) (i) (iv) | Infrared waves are used to treat muscular strain. Radio waves are used for broadcasting. X-rays are used to detect the fracture of bones. Ultraviolet rays are absorbed by the ozone layer of the atmosphere. Answer: (a) P Q R S (i) (ii) (iii) (iv) | ||||||||||
Q: The magnetic field in a traveling electromagnetic wave has a peak value of 20 nT. The peak value of electric field strength is:
| In an electromagnetic wave, the peak value of the electric field (E0) and peak value of magnetic field (B0) are related by E0 = B0C E0 = (20 × 10-9 T) (3 × 108 m s-1) = 6 V/m Answer: (c) 6 V/m | ||||||||||
Q: During the propagation of electromagnetic waves in a medium
| In an electromagnetic wave, energy is equally divided between the electric and the magnetic fields. Answer: (d) The electric energy density is equal to the magnetic energy density | ||||||||||
Q: The energy associated with electric field is (UE) and with magnetic field is (UB) for an electromagnetic wave in free space. Then
| Answer: (c) UE = UB | ||||||||||
Q: An electromagnetic wave of frequency = 3.0 MHz passes from a vacuum into a dielectric medium with permittivity = 4.0. Then (a) wavelength is doubled and the frequency remains unchanged (b) wavelength is doubled and frequency becomes half (c) wavelength is halved and frequency remains unchanged (d) wavelength and frequency both remain unchanged | Determination of frequency of the EM wave when passes from vacuum to dielectric medium:
Thus, the frequency of the EM wave when it passes from a vacuum to a dielectric medium will not change. | ||||||||||
Also Read: JEE Main Syllabus 2025
Important Topics From Electromagnetic Wave for JEE Main 2025
Candidates can check the important topics from the Electromagnetic Wave chapter for the JEE main 2025 exam below. Going through the important topics will help the candidates to focus on the topics that hold maximum marks in the exam:
- Properties of Electromagnetic Waves
- Electromagnetic Wave Equations
- Electromagnetic Wave Interference and Diffraction
- Polarisation of Light
- Polarisation of Electromagnetic Waves
- Polarisation by Double Refraction
- Electromagnetic Wave Applications
- Electromagnetic Spectrum
- Electromagnetic Wave Propagation
- Huygens' Principle
Check JEE Main Physics Syllabus 2025 in Details Here!
Electrostatics Weightage in JEE Main 2025
To understand the importance of Electromagnetic Waves in the JEE Main 2025 exam, candidates can check the weightage of the Electromagnetic waves chapter in the JEE main previous year question papers. Check the weightage below in the table:
Electrostatics Weightage in Previous Year’s JEE Main Exam | |
2024 | 2 |
2023 | 2 |
2022 | 2 |
2021 | 2 |
2020 | 2 |
2019 | 2 |
JEE Main Electromagnetic Waves Previous Years Questions
Candidates can check the previous year's questions from the electromagnetic wave chapter in the JEE main exam.
Q: In a medium, the speed of light wave decreases to 0.2 times its speed in free space The ratio of relative permittivity to the refractive index of the medium is x:1. The value of x is _________.
(Given speed of light in free space = 3×108 m s−1 and for the given medium μr=1)
January 31, 2023 Morning Shift
Q: A point source of light is placed at the center of curvature of a hemispherical surface. The source emits a power of 24 W. The radius of curvature of hemisphere is 10 cm and the inner surface is completely reflecting. The force on the hemisphere due to the light falling on it is ____________ × 10−8 N.
January 30, 2023 Morning Shift
Also Read: JEE Main Eligibility Criteria 2025
Q: Nearly 10% of the power of a 110 W light bulb is converted to visible radiation. The change in average intensities of visible radiation, at a distance of 1 m from the bulb to a distance of 5 m is a×10−2 W/m2. The value of 'a' will be _________.
July 29, 2022, Evening Shift
Q: The displacement current of 4.425 μA is developed in the space between the plates of the parallel plate capacitor when voltage is changing at a rate of 106 Vs−1. The area of each plate of the capacitor is 40 cm2. The distance between each plate of the capacitor is x × 10−3 m. The value of x is __________. (Permittivity of free space, E0 = 8.85 × 10−12 C2 N−1 m−2).
July 29, 2022 Evening Shift
Q: The intensity of the light from a bulb incident on a surface is 0.22 W/m2. The amplitude of the magnetic field in this light wave is ______________ × 10−9 T.
(Given : Permittivity of vacuum E0 = 8.85 × 10−12 C2 N−1-m−2, speed of light in vacuum c = 3 × 108 ms−1)
June 29, 2022 Morning Shift
Q: The electric field in an electromagnetic wave is given by E = (50 NC−1) sinω (t − x/c). The energy contained in a cylinder of volume V is 5.5 × 10−12 J. The value of V is _____________ cm3. (given E0 = 8.8 × 10−12C2N−1m−2)
August 31, 2021 Morning Shift
Q: A plane electromagnetic wave with a frequency of 30 MHz travels in free space. At a particular point in space and time, the electric field is 6 V/m. The magnetic field at this point will be x × 10−8 T. The value of x is ___________.
August 21, 2021 Evening Shift
Q: The electric field in a plane electromagnetic wave is given by E→=200cos[(0.5×103m)x−(1.5×1011rads×t)]Vmj^. If this wave falls normally on a perfectly reflecting surface having an area of 100 cm2. If the radiation pressure exerted by the E.M. wave on the surface during a 10-minute exposure is x109Nm2. Find the value of x.
August 26, 2021 Morning Shift
We have provided the complete details of the electromagnetic wave questions along with the important practice questions and questions from the previous year.
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