What does Electromagnetic Waves cover for NEET Physics?

5 lessons: Applications EM Waves, Displacement Current, EM Spectrum, EM Waves Characteristics and Transverse Nature EM.

How often has Electromagnetic Waves come up in NEET past papers?

Our set of verified past papers has 12 questions from this unit, from NEET 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Each is answered against the official NTA key.

Is the Electromagnetic Waves material free?

Yes. All 5 lessons and 40 practice questions are free, with no login needed.

Electromagnetic Waves

5 lessons

Topic index in NCERT order

5 of 5 lessons by the NCERT chapter they teach from, in book order. The page is the first printed page of your NCERT book the lesson cites; PYQs are the past NEET questions on that topic.

Class 12 Physics, Chapter 8

Applications EM Waves

8 MCQs1 PYQsWorked example

Easy Recall (3)Direct Application (3)Concept Trap (2)

Displacement Current

8 MCQs2 PYQs1 revision cardWorked example

Easy Recall (2)Concept Trap (2)Direct Application (2)Calculation (2)

EM Spectrum

8 MCQs2 PYQsWorked example

Easy Recall (3)Direct Application (3)Calculation (1)Concept Trap (1)

EM Waves Characteristics

8 MCQs6 PYQs3 revision cardsWorked example

Easy Recall (3)Direct Application (3)Calculation (1)Concept Trap (1)

Transverse Nature EM

8 MCQsWorked example

Easy Recall (2)Concept Trap (2)Direct Application (2)Calculation (2)

Past-paper questions from this unit

12 questions from NEET 2020, 2021, 2022, 2023, 2024, 2025, 2026. Answers verified against NTA official keys.

By year in our set: 2020 (1) · 2021 (2) · 2022 (3) · 2023 (1) · 2024 (1) · 2025 (2) · 2026 (2)

NEET 2026

An electromagnetic wave travelling in a lossless dielectric medium having a dielectric constant ε_r = 9, has the electric field E_x = E₀ sin(kz − 2π × 10⁶ t) Vm⁻¹ where E₀ is the amplitude and k is the wave vector. Among the following options, the incorrect choice is :

1The speed of the electromagnetic wave inside the medium is 10⁸ ms⁻¹

2The wavelength of the electromagnetic wave inside the medium is 300 m

3The magnetic field is given by the relation B_y = (B₀/v) sin(kz − 2π × 10⁶ t) where v is the speed of the electromagnetic wave inside the medium

4The direction of propagation of the electromagnetic wave is along +z

NTA Answer: Option multi:2,3(final)

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Lesson: EM Spectrum

NEET 2026

The following table presents the part of the electromagnetic spectrum and their corresponding major applications. P: Microwave, Q: UV rays, R: Gamma rays, S: Radio wave. I: For purifying the water, II: For warming the food, III: For AM and FM communication systems, IV: For treating the Cancer cells. The correct option is :

1P-I, Q-II, R-III, S-IV

2P-I, Q-IV, R-II, S-III

3P-II, Q-I, R-IV, S-III

4P-II, Q-IV, R-III, S-I

NTA Answer: Option 3(final)

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Lesson: EM Waves Characteristics

NEET 2025

The electric field in a plane electromagnetic wave is given by E_z = 60 cos (5x + 1.5 × 10⁹ t) V/m. Then expression for the corresponding magnetic field is (here subscripts denote the direction of the field) :

1B_y = 60 sin (5x + 1.5 × 10⁹ t) T

2B_y = 2 × 10⁻⁷ cos (5x + 1.5 × 10⁹ t) T

3B_x = 2 × 10⁻⁷ cos (5x + 1.5 × 10⁹ t) T

4B_z = 60 cos (5x + 1.5 × 10⁹ t) T

NTA Answer: Option 2(final)

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Lesson: Displacement Current

NEET 2025

A parallel plate capacitor made of circular plates is being charged such that the surface charge density on its plates is increasing at a constant rate with time. The magnetic field arising due to displacement current is:

1Zero between the plates and non-zero outside

2Zero at all places

3Constant between the plates and zero outside the plates

4Non-zero everywhere with maximum at the imaginary cylindrical surface connecting peripheries of the plates

NTA Answer: Option 4(final)

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Lesson: EM Waves Characteristics

NEET 2024Revised key

The property which is not of an electromagnetic wave travelling in free space is that:

1They are transverse in nature

2The energy density in electric field is equal to energy density magnetic field

3They travel with a speed equal to 1/√(µ₀ε₀)

4They originate from charges moving with uniform speed

NTA Answer: Option 4(revised_final)

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Lesson: EM Waves Characteristics

NEET 2023

In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of 2.0 × 10¹⁰ Hz and amplitude 48 V m⁻¹. Then the amplitude of oscillating magnetic field is (Speed of light in free space = 3 × 10⁸ m s⁻¹)

11.6 × 10⁻⁸ T

21.6 × 10⁻⁷ T

31.6 × 10⁻⁶ T

41.6 × 10⁻⁹ T

NTA Answer: Option 2(final)

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Lesson: EM Spectrum

NEET 2022

Match List-I with List-II List-I (Electromagnetic waves) List-II (Wavelength) (a) AM radio waves (i) 10–10 m (b) Microwaves (ii) 102 m (c) Infrared radiations (iii) 10–2 m (d) X-rays (iv) 10–4 m Choose the correct answer from the options given below

1(a) - (ii), (b) - (iii), (c) - (iv), (d) - (i)

2(a) - (iv), (b) - (iii), (c) - (ii), (d) - (i)

3(a) - (iii), (b) - (ii), (c) - (i), (d) - (iv)

4(a) - (iii), (b) - (iv), (c) - (ii), (d) - (i)

NTA Answer: Option 1(final)

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Lesson: EM Waves Characteristics

NEET 2022

When light propagates through a material medium of relative permittivity εᵣ and relative permeability μᵣ, the velocity of light, v is given by (c-velocity of light in vacuum)

1v = c/√(εᵣμᵣ)

2v = c

3v = √(μᵣ/εᵣ)

4v = √(εᵣ/μᵣ)

NTA Answer: Option 1(final)

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Lesson: Applications EM Waves

NEET 2022

The energy that will be ideally radiated by a 100 kW transmitter in 1 hour is

11 × 10⁵ J

236 × 10⁷ J

336 × 10⁴ J

436 × 10⁵ J

NTA Answer: Option 2(final)

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Lesson: Displacement Current

NEET 2021

A capacitor of capacitance 'C', is connected across an ac source of voltage V, given by V = V₀sinωt. The displacement current between the plates of the capacitor, would then be given by

1I_d = V₀ωC sinωt

2I_d = V₀ωC cosωt

3I_d = (V₀/(ωC)) cosωt

4I_d = (V₀/(ωC)) sinωt

NTA Answer: Option 2(final)

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Lesson: EM Waves Characteristics

NEET 2021

For a plane electromagnetic wave propagating in x-direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?

1−+ − + , jk jk

2++ , j kj k

3−+ − − , jk jk

4+ −− , jk jk

NTA Answer: Option 3(final)

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Lesson: EM Waves Characteristics

NEET 2020

The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is : (c=speed of electromagnetic waves)

11 : c2

2c : 1

31 : 1

41 : c

NTA Answer: Option 3(final)

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Exam traps and common mistakes in this unit

Lesson: EM Waves Characteristics

Trap

EM wave E0 vs B0 unit confusion

Category: Unit Conversion

Student reports E in T or B in V/m, conflating the two amplitudes. They differ by factor c; same SI dimensions in Gaussian units only.

When it triggers

EM wave question gives E0 (V/m) and asks for B0 (T) or vice versa.

How to avoid

Always: E (V/m) = c × B (T). c ≈ 3×10⁸ converts. E and B have different SI dimensions.

Lesson: EM Waves Characteristics

Mistake

Confuses units of E (V/m) and B (T) in EM wave problems.

Root cause: unit error

Correction

E (V/m) = c × B (T). The amplitudes differ by factor c≈3×10⁸. They have different SI dimensions (V/m vs T = kg/(A·s²)).

Formulas in this unit

Lesson: Displacement Current

Displacement current

I_{d} = ε_{0} \frac{d Φ _{E}}{d t}

Current associated with changing electric flux. Closes Ampere's law for time-varying fields.

Symbol	Quantity	SI Unit
I_d	displacement current	A
Phi_E	electric flux	V*m
eps0	permittivity	F/m

Valid when

Time-varying E field
Capacitor or vacuum region

Lesson: EM Waves Characteristics

Intensity of EM wave

I = \frac{1}{2} c ε_{0} E_{0}^{2}

Average power per unit area carried by EM wave with peak field E0.

Symbol	Quantity	SI Unit
I	intensity	W/m^2
E0	peak field	V/m
c	speed	m/s
eps0	permittivity	F/m

Valid when

Plane EM wave
Far-field

Lesson: EM Waves Characteristics

E/B ratio in EM wave

\frac{E _{0}}{B _{0}} = c

In an EM plane wave, the amplitudes of E and B are related by speed of light.

Symbol	Quantity	SI Unit
E0	E peak	V/m
B0	B peak	T

Valid when

Plane wave
Vacuum

Lesson: EM Waves Characteristics

Speed of EM waves in vacuum

c = \frac{1}{μ _{0} ε _{0}}

Speed of EM waves in vacuum from Maxwell's equations. ~3e8 m/s.

Symbol	Quantity	SI Unit
c	speed in vacuum	m/s
mu0	permeability	T*m/A
eps0	permittivity	F/m

Valid when

Vacuum or air
No dispersion at given frequency

NEET question patterns in this unit

Lesson: Displacement Current

Capacitor with changing voltage: displacement current I_d = ε_0 dΦ_E/dt = capacitor I.

Multi StepMedium

Common distractors

treats displacement as real current

Conflates conduction with displacement

Lesson: EM Spectrum

Identify wavelength range or property of given EM band.

RecallEasy

Common distractors

swaps bands

Confuses microwave with infrared

Lesson: EM Waves Characteristics

EM wave amplitude relation: E0 = c B0. Find B given E or vice versa.

Direct ApplicationEasy

Common distractors

forgets c conversion

Equates E and B without c factor

Questions about this unit

What does Electromagnetic Waves cover for NEET Physics?: 5 lessons: Applications EM Waves, Displacement Current, EM Spectrum, EM Waves Characteristics and Transverse Nature EM.
How often has Electromagnetic Waves come up in NEET past papers?: Our set of verified past papers has 12 questions from this unit, from NEET 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Each is answered against the official NTA key.
Is the Electromagnetic Waves material free?: Yes. All 5 lessons and 40 practice questions are free, with no login needed.