NEET PhysicsUpdated 19 Oct 2026

Electromagnetic Waves: NEET PYQs and weightage

Electromagnetic Waves carries 2.6 of 100 Physics marks in NEET by past-paper share: 20 of the 758 tagged NEET Physics PYQs in the ViJEEta bank (NEET 2013–2026). It ranks 23 of 30 Physics chapters.

Take the 25-question Electromagnetic Waves test Formula sheet ↓All NEET Physics chapters

2.6/100 Weight in Physics

Exam importance (3/5, by past-paper share)

20 NEET PYQs

148 Practice questions

141 With measured difficulty

How the weight is computed: this chapter's tagged NEET PYQs divided by all tagged NEET Physics PYQs in the bank (20 of 758), times 100, with repeated questions counted once. The bank does not store the year of each NEET question, so none is printed. Computed from the bank at build time. Updated 19 Oct 2026.

Electromagnetic Waves: formula sheet for NEET

14 formulas, each with when to use it. Copy it onto one page of your notebook: that page is this chapter's handbook.

Field ratio
$E_{0} = c B_{0}$
$E = c B (at every instant)$
Use it when: One field's amplitude is given and you need the other ( $E$ in V/m, $B$ in tesla, so $B$ comes out tiny).
Speed in vacuum
$c = \frac{1}{μ _{0} ε _{0}} = 3 \times 1 0^{8} m/s$
Use it when: Asked to link $c$ with $μ_{0}$ and $ε_{0}$ , or to check a dimension question.
Wave relations
$c = ν λ = \frac{ω}{k}$
$k = \frac{2 π}{λ}$
$ω = 2 π ν$
Use it when: You need to read $λ$ or $ν$ off a given wave equation.
Wave equations
$E_{x} = E_{0} sin (k z - ω t)$
$B_{y} = B_{0} sin (k z - ω t)$
Use it when: Writing $E$ from a given $B$ or the reverse (same phase, perpendicular axes).
Direction rule
$direction of travel = direction of E \times B$
Use it when: Finding the axis of $B$ from $E$ and the propagation direction (e.g. $\hat{j} \times \hat{k} = \hat{i}$ ).
Intensity
$I = \frac{E _{0} B _{0}}{2 μ _{0}} = \frac{E _{0}^{2}}{2 μ _{0} c} = \frac{1}{2} ε_{0} c E_{0}^{2}$
Use it when: You need average power per unit area from field amplitudes ( $I$ in $W/m^{2}$ ).
Poynting vector
$S = \frac{1}{μ _{0}} E \times B$
Use it when: Asked for the instantaneous energy flow rate per unit area and its direction.
Radiation pressure (normal incidence)
$p = \frac{I}{c} (total absorption)$
$p = \frac{2 I}{c} (perfect reflector)$
Use it when: Light falls on a surface and you need the pressure or force ( $F = p A$ ).
Momentum flow
$\frac{1}{A} \frac{d p}{d t} = \frac{S}{c} = \frac{E B}{μ _{0} c}$
Use it when: Asked how much momentum per second per unit area the wave delivers.
Displacement current
$i_{d} = ε_{0} \frac{d Φ _{E}}{d t}$
Use it when: A capacitor is charging; between the plates $i_{d}$ equals the conduction current $i$ in the wires.
Ampere-Maxwell law
$\oint B \cdot d l = μ_{0} i_{c} + μ_{0} ε_{0} \frac{d Φ _{E}}{d t}$
Use it when: Finding $B$ between capacitor plates, where only the displacement current exists.
Speed in a medium
$v = \frac{1}{μ ε} = \frac{c}{K K _{m}}$
Use it when: The wave is in a material with given permittivity and permeability (or $K$ and $K_{m}$ ).
Photon energy
$E = h ν = \frac{h c}{λ}$
Use it when: Converting the frequency or wavelength of any part of the spectrum to energy.
Spectrum order (increasing wavelength)
$γ -rays < X-rays < UV < visible (400 to 700 nm) < infrared < microwaves < radio$
Use it when: Ranking waves by $λ$ , $ν$ or photon energy ( $ν$ and $E$ run the opposite way).

Trap

The sign in the phase sets the direction. sin(kx − ωt) travels along +x, but sin(kx + ωt) travels along −x. Then fix the axis of the other field with E × B along that direction, not along +x.

How does NEET ask Electromagnetic Waves?

8 real previous-year questions from this chapter, as printed in the paper, each with its worked solution. Answer the first one here with no sign-in.

Q1PhysicsNEET UG PYQBasics of Electromagnetic Waves

Try right here · No sign-in

The electric field in a plane electromagnetic wave is given by

E_{z} = 60 cos (5 x + 1.5 \times 10^{9} t) V / m

Then expression for the corresponding magnetic field is (here subscripts denote the direction of the field):

Answer key (C) & worked solution

Correct answer: Option C

E_{Z} = 60 cos (5 x + 1.5 \times 10^{9} t) v / m

Here,

E_{0} = 60

B_{0} = \frac{E _{0}}{c} = \frac{60}{3 \times 10 ^{8}} = 20 \times 1 0^{- 8} = 2 \times 1 0^{- 7}

B

Should be perpendicular to

E

∴ B_{y} = 2 \times 1 0^{- 7} cos (5 x + 1.5 \times 10^{9} t) T

Q2PhysicsNEET UG PYQDisplacement Current

A parallel plate capacitor is charged by connecting it to a battery through a resistor. If I is the current in the circuit, then in the gap between the plates:

ADisplacement current of magnitude equal to I flows in the same direction as I.

BDisplacement current of magnitude equal to I flows in a direction opposite to that of I.

CDisplacement current of magnitude greater then I flows but can be in any direction.

DThere is no current.

Answer key (A) & worked solution

Correct answer: Option A

Displacement current of magnitude equal to I flows in the same direction as I.

Q3PhysicsNEET UG PYQDisplacement Current

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:

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

BZero between the plates and non-zero outside

CZero at all places

DConstant between the plates and zero outside the plates

Answer key (A) & worked solution

Correct answer: Option A

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

\oint B . d l = μ_{0} (i_{C} + ε_{0} \frac{\partial ϕ}{\partial t})

∴

Maxwell Ampere law In the gap, there’s no conduction but there is displacement current due to changing electric field. This current leads to magnetic field in the region If increases radially with in the places, reaching maximum at the edge.

Q4PhysicsNEET UG PYQBasics of Electromagnetic Waves

In an electromagnetic wave in free space the root mean square value of the electric field is

E_{r m s} = 6 V / m .

The peak value of the magnetic field is(given

3 \times 1 0^{8} m / s

and

2 = 1.41

)

0.70 \times 1 0^{- 8} T

4.23 \times 1 0^{- 8} T

1.41 \times 1 0^{- 8} T

2.82 \times 1 0^{- 8} T

Answer key (D) & worked solution

Correct answer: Option D

\frac{E _{r m s}}{B _{r m s}} = c

B_{r m s} = \frac{E _{r m s}}{c}

= \frac{6}{3 \times 10 ^{8}}

B_{r m s} = 2 \times 1 0^{- 8}

B_{r m s} = \frac{B _{0}}{2}

B_{0} = 2 \times B_{r m s}

= 2 \times 2 \times 1 0^{- 8}

= 2.82 \times 1 0^{- 8} T

Q5PhysicsNEET UG PYQBasics of Electromagnetic Waves

An em wave is propagating in a medium with a velocity

V = V \hat{i}

. The instantaneous oscillating electric field of this em wave is along +y axis. Then the direction of oscillating magnetic field of the em wave will be along

A-y direction

B+z direction

C-z direction

D-x direction

Answer key (B) & worked solution

Correct answer: Option B

E \times B = V

(E \hat{j}) \times (B) = V \hat{i}

So,

B = B \hat{k}

Direction of propagation is along +z direction.

Q6PhysicsNEET UG PYQDisplacement Current

A capacitor of capacitance ‘C’, is connected across an ac source of voltage V, given by V = V

_{0}

sin ωt The displacement current between the plates of the capacitor, would then be given by:

I_{d} = \frac{V _{0}}{ω C} sin ω t

I_{d} = V_{0} ω C sin ω t

I_{d} = V_{0} ω C cos ω t

I_{d} = \frac{V _{0}}{ω C} cos ω t

Answer key (C) & worked solution

Correct answer: Option C

Conduction current in case of capacitor with Ac source:

I_{c} = V_{0} ω C cos ω t

∴

Displacement current will be :

V_{0} ω C cos ω t

Q7PhysicsNEET UG PYQBasics of Electromagnetic Waves

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

AThe energy density in electric field is equal to energy density in magnetic field

BThey travel with a speed equal to

\frac{1}{μ _{0} \in _{0}}

CThey originate from charges moving with uniform speed

DThey are transverse in nature.

Answer key (C) & worked solution

Correct answer: Option C

EM wave needs acc. change

Q8PhysicsNEET UG PYQElectromagnetic Spectrum

The following table presents the part of the electromagnetic spectrum and their corresponding major applications. Part of the electromagnetic spectrumApplicationsP.MicrowaveI.For purifying the waterQUV raysII.For warming the food R.Gamma rays III.For AM and FM communication systems S.Radio wave IV.For treating the Cancer cells The correct option is:

AP-I, Q-IV, R-II, S-III

BP-II, Q-I, R-IV, S-III

CP-II, Q-IV, R-III, S-I

DP-I, Q-II, R-III, S-IV

Answer key (B) & worked solution

Correct answer: Option B

Part of the electromagnetic spectrumApplicationsMicrowaveFor warming of food UV rays For purifying the waterGamma rays For treating the cancer cells Radio waveFor AM and FM communication systems

Which topics in Electromagnetic Waves carry the most questions?

All 4 topics, by tagged PYQs, then practice questions. Counted from the bank. Updated 19 Oct 2026.

Topic	PYQs	Practice questions
Basics of Electromagnetic Waves	12	104
Electromagnetic Spectrum	4	24
Displacement Current	4	19
Miscellaneous Examples	0	1

Why does Electromagnetic Waves show "–" until you answer 3 questions?

Unknown is not zero. Until you answer at least 3 graded questions in Electromagnetic Waves, ViJEEta shows – instead of a zero or a 50% default. Book exercises can raise chapter mastery up to 0.60, adaptive practice up to 0.75, and only a timed chapter test or mock can certify 0.80 and above.

How ViJEEta scores you

What happens when you test Electromagnetic Waves?

Every chapter test is 25 questions. It starts at moderate difficulty and adapts after each saved answer. If you open a solution before answering, that attempt earns no credit, so your mastery stays honest.

Start the Electromagnetic Waves test

Chapters either side of Electromagnetic Waves by weight

Electric Charges and Fields Weight 2.6/100 Electromagnetic Induction Weight 2.6/100 Motion in a Plane Weight 2.4/100 Thermal Properties of Matter Weight 2.4/100

Electromagnetic Waves: NEET PYQs and weightage

Electromagnetic Waves: formula sheet for NEET

Field ratio

Speed in vacuum

Wave relations

Wave equations

Direction rule

Intensity

Poynting vector

Radiation pressure (normal incidence)

Momentum flow

Displacement current

Ampere-Maxwell law

Speed in a medium

Photon energy

Spectrum order (increasing wavelength)

How does NEET ask Electromagnetic Waves?

Which topics in Electromagnetic Waves carry the most questions?

Why does Electromagnetic Waves show "–" until you answer 3 questions?

What happens when you test Electromagnetic Waves?

Chapters either side of Electromagnetic Waves by weight