Electromagnetic Waves
84 JEE Physics previous year questions on Electromagnetic Waves — options free on every question; 8 include the answer & explanation free, the rest unlock with PYQ Pass.
A plane electromagnetic wave of frequency 20 MHz travels in free space along the \(+x\) direction. At a particular point in space and time, the electric field vector of the wave is \({\mathrm{E}}_{y}=9.3{\mathrm{Vm}}^{-1}\). Then, the magnetic field vector of the wave at that point is
\({\mathrm{B}}_{z}=3.1\times {10}^{-8}\mathrm{T}\)
\(C=\frac{E}{B}\\ B=\frac{E}{C}\\ B=\frac{9.3}{3\times {10}^{8}}\\ B=3.1\times {10}^{-8}T\)
The value of \({E}_{0}\) is 9.3 V/m and c is 3 × \({10}^{8}\) m/s. Find the value of B0.
(Shift - II Memory Based)
\(3.1\times {10}^{-8}\)
The relationship between the electric field (\({E}_{0}\)) and magnetic field (\({B}_{0}\)) in electromagnetic waves is given by:
\({E}_{0}=c⋅{B}_{0}\)
Rearranging for \({B}_{0}\):
\({B}_{0}=\frac{{E}_{0}}{c}\)
Substitute the given values:
\({B}_{0}=\frac{9.3}{3\times 1{0}^{8}}\)
Simplify:
\({B}_{0}=3.1\times 1{0}^{−8}\text{ }\text{T}\)
Rounding \({B}_{0}\) is approximately 3 (depending on units being normalized for \({B}_{0}\)).
Correct answer: (d).
Due to presence of an em-wave whose electric component is given by \(E=100\sin (\omega t-kx)N{C}^{-1}\), a cylinder of length 200 cm holds certain amount of em-energy inside it. If another cylinder of same length but half diameter than previous one holds same amount of em-energy, the magnitude of the electric field of the corresponding em-wave should be modified as
200 \sin (\omega \mathrm{t}-\mathrm{kx}) \mathrm{NC}^{-1}
\(\text{ Average energy density }=\frac{1}{2}{\epsilon }_{0}{E}_{0}^{2}\\ \text{ Average energy }\left({E}_{AV}\right)=\frac{1}{2}{\epsilon }_{0}{E}_{0}^{2}AL\\ =\frac{1}{2}{\epsilon }_{0}{E}_{0}^{2}\pi {\left(\frac{D}{2}\right)}^{2}L\\ =\frac{\pi {\epsilon }_{0}{E}_{0}^{2}{D}^{2}L}{8}\\ As,{E}_{1}={E}_{2}\\ \frac{\pi {\epsilon }_{0}{E}_{01}^{2}{D}^{2}L}{8}=\frac{\pi {\epsilon }_{0}{E}_{02}^{2}{\left(\frac{D}{2}\right)}^{2}L}{8}\\ \Rightarrow {E}_{01}^{2}=\frac{{E}_{02}^{2}}{4}\\ {E}_{02}=2{E}_{01}=200\)
A magnetic field vector in an electromagnetic wave is represented by \(\vec{B}={B}_{0}\sin \left(2\pi \nu t-\frac{2\pi x}{\lambda }\right)\hat{j}\). Its associated electric field vector is ________
[JEE Main 2026, 4 Apr (Shift 2)]
\(\vec{E}=-\nu \lambda {B}_{0}\sin \left(2\pi \nu t-\frac{2\pi x}{\lambda }\right)\hat{k}\)
\(\vec{B}={B}_{0}\sin \left(2\pi \nu t-\frac{2\pi x}{\lambda }\right)\hat{j}\)
Since spatial term contains only \(x\) with negative sign \((\omega t-kx)\), wave propagates along \(+\hat{x}\).
\(\hat{E}\times \hat{B}=\hat{C}\)
\(\hat{B}=\hat{j},\hat{C}=\hat{j}\)
\(\hat{E}\times \hat{j}-\hat{i}\Rightarrow \hat{E}=-\hat{k}\)
\({E}_{0}=c{B}_{0}=\nu \lambda {B}_{0}\)
\(\vec{E}=-\nu \lambda {B}_{0}\sin \left(2\pi \nu t-\frac{2\pi x}{\lambda }\right)\hat{k}\)
The electric field in an electromagnetic wave is given by \(\vec{E}=\hat{i}40\cos \omega (t-z/c)N{C}^{-1}\). The magnetic field induction of this wave is (in SI unit) :
\(\vec{B}=\hat{j}\frac{40}{c}\cos \omega (t-z/c)\)
1. Direction: The wave propagates along the \(+z\)-axis (from \(t - z/c\)). The electric field \(\vec{E}\) is along the \(+x\)-axis (\(\hat{i}\)).
The direction of propagation is given by \(\vec{E} \times \vec{B}\).
Since \(\hat{i} \times \hat{j} = \hat{k}\), the magnetic field \(\vec{B}\) must be along the \(+y\)-axis (\(\hat{j}\)).
2. Amplitude: The amplitude of the magnetic field is \(B_{0}=\frac{E_{0}}{c}\).
Given \(E_{0}=40\), so \(B_{0}=\frac{40}{c}\).
Combining these, \(\vec{B}=\hat{j}\frac{40}{c}\cos\omega(t-z/c)\).
If \({\mu }_{0}\) and \({\epsilon }_{0}\) are the permeability and permittivity of free space, respectively, then the dimension of \(\left(\frac{1}{{\mu }_{0}{\epsilon }_{0}}\right)\) is :
[JEE Main 2025, 2 Apr (Shift 2)]
\({\mathrm{L}}^{2}{\mathrm{T}}^{-2}\)
\(C=\frac{1}{\sqrt{\mu_0 \varepsilon_0}} \Rightarrow \frac{1}{\mu_0 \varepsilon_0}=C^2=L^2 T^{-2}\)
In the given electromagnetic wave \(E _{ y }=600 \sin (\omega t - kx ) Vm ^{-1}\), intensity of the associated light beam is (in \(W / m ^2:\left(\right.\) Given \(\left.\epsilon_0=9 \times 10^{-12} C ^2 N ^{-1} m ^{-2}\right)\)
486
\(\mathrm{I}=\frac{1}{2}{\epsilon }_{0}{\mathrm{E}}_{0}^{2}\mathrm{c}\)
\(\mathrm{I}=\frac{1}{2}\times 9\times {10}^{-12}\times (600{)}^{2}\times 3\times {10}^{8}\)
\(I=\frac{9\times 3}{2}\times 36\times {10}^{4}\times {10}^{-12}\times {10}^{8}\)
\(I=27\times 18\)
\(I=486\frac{\text{ watt }}{{\mathrm{m}}^{2}}\)
An electromagnetic wave propagates in the +X -direction. Then, the electric field and magnetic field are directed along
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A parallel plate capacitor has a capacitance C \(=200 \ pF\). It is connected to \(230 \ V\) ac supply with an angular frequency \(300 \ rad / s\). The rms value of conduction current in the circuit and displacement current in the capacitor respectively are :
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Due to presence of an em-wave whose electric component is given by \(E=100\sin (\omega t-kx)N{C}^{-1}\), a cylinder of length 200 cm holds certain amount of em-energy inside it. If another cylinder of same length but half diameter than previous one holds same amount of em-energy, the magnitude of the electric field of the corresponding em-wave should be modified as
[JEE Main 2025, 28 Jan (Shift 1)]
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Arrange the following in the ascending order of wavelength \((\lambda )\) :
(A) Microwaves \(\left({\lambda }_{1}\right)\)
(B) Ultraviolet rays \(\left({\lambda }_{2}\right)\)
(C) Infrared rays \(\left({\lambda }_{3}\right)\)
(D) X-rays \(\left({\lambda }_{4}\right)\)
Choose the most appropriate answer from the options given below :
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Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Electromagnetic waves carry energy but not momentum.
Reason (R): Mass of a photon is zero.
In the light of the above statements, choose the most appropriate answer from the options given below :
[JEE Main 2025, 29 Jan (Shift 1)]
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In the given electromagnetic wave \(E _{ y }=600 \sin (\omega t - kx ) Vm ^{-1}\), intensity of the associated light beam is (in \(W / m ^2:\left(\right.\) Given \(\left.\epsilon_0=9 \times 10^{-12} C ^2 N ^{-1} m ^{-2}\right)\)
[JEE Main 2024, 6 Apr (Shift 2)]
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The electric field of an electromagnetic wave in free space is \(\vec{\mathrm{E}}=57\cos \left[7.5\times {10}^{6}\mathrm{t}-5\times {10}^{-3}(3x+4y)\right](4\hat{i}-3\hat{j})N/C.\) The associated magnetic field in Tesla is
[JEE Main 2025, 23 Jan (Shift 1)]
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Find the equation of the magnetic field for the given equation of the electric field (for an EM wave): \(\vec{\mathrm{E}}={\mathrm{E}}_{0}(4\hat{\mathrm{i}}−3\hat{\mathrm{j}})\cos (\mathrm{ωt}−\mathrm{kz})\mathrm{.}\)
(Shift I Memory Based)
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Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Electromagnetic waves carry energy but not momentum.
Reason (R): Mass of a photon is zero.
In the light of the above statements, choose the most appropriate answer from the options given below :
[JEE Main 2025, 29 Jan (Shift 1)]
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A plane electromagnetic wave of frequency 20 MHz travels in free space along the \(+x\) direction. At a particular point in space and time, the electric field vector of the wave is \({\mathrm{E}}_{y}=9.3{\mathrm{Vm}}^{-1}\). Then, the magnetic field vector of the wave at that point is
[JEE Main 2025, 23 Jan (Shift 2)]
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The value of \({E}_{0}\) is 9.3 V/m and c is 3 × \({10}^{8}\) m/s. Find the value of B0.
(Shift - II Memory Based)
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The electric field in an electromagnetic wave is given by \(\vec{E}=\hat{i}40\cos \omega (t-z/c)N{C}^{-1}\). The magnetic field induction of this wave is (in SI unit) :
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A plane electromagnetic wave of frequency 20 MHz travels in free space along the \(+x\) direction. At a particular point in space and time, the electric field vector of the wave is \({\mathrm{E}}_{y}=9.3{\mathrm{Vm}}^{-1}\). Then, the magnetic field vector of the wave at that point is
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A displacement current of 4.0 A can be set up in the space between two parallel plates of \(6\mu F\) capacitor. The rate of change of potential difference across the plates of the capacitor is nearly \(\alpha \times {10}^{6}\mathrm{V}/\mathrm{s}.\)
The value of \(\alpha\) is ______.
[JEE Main 2026, 5 Apr (Shift 1)]
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Find the equation of the magnetic field for the given equation of the electric field (for an EM wave): \(\vec{\mathrm{E}}={\mathrm{E}}_{0}(4\hat{\mathrm{i}}−3\hat{\mathrm{j}})\cos (\mathrm{ωt}−\mathrm{kz})\mathrm{.}\)
(Shift I Memory Based)
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The electric field of an electromagnetic wave in free space is represented as \(\vec{E}={E}_{0}\cos (\omega t-kz)\hat{i}\). The corresponding magnetic induction vector will be :
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For an electromagnetic wave propagating through vacuum, \(\vec{k}\), \(\vec{E}\) and \(\omega\) represent propagation vector, electric field and angular frequency, respectively. The magnetic field associated with this wave is represented by:
[JEE Main 2026, 6 Apr (Shift 2)]
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In an electromagnetic wave, the magnetic field is given as \(\vec{B}=\left(\frac{\sqrt{3}}{2} \hat{\imath}+\frac{1}{2} \hat{\jmath}\right) 30 \sin (\omega t-k z)\), the corresponding electric field is
(Shift - II Memory Based)
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Arrange the following in order of decreasing wavelength.
a: Microwave b: Ultraviolet
c: Infrared d: X-rays
(Shift II memory based)
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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 :
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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Electromagnetic waves exert pressure on the surface on which they fall.
Reason (R): There is no mass associated with electromagnetic waves.
In the light of the above statements, choose the correct answer from the options given below:
[JEE Main 2026, 5 Apr (Shift 2)]
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A parallel plate capacitor has a total plate area of \(16\text{ }{\text{cm}}^{2}\) and a distance of \(10\text{ }\text{cm}\) between the plates. This capacitor is connected to an AC source, and at a given instant, the current in the circuit is \(6\text{ }\text{A}\). Assuming a smaller region of area \(3.2\text{ }{\text{cm}}^{2}\) lies between and parallel to the plates, what is the displacement current in this region?
(Shift II Memory Based)
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In the four regions, I, II, III and IV, the electric fields are described as :
Region I : \(E _{ x }= E _0 \sin ( kz -\omega t )\)
Region II : \(E _{ x }= E _0\)
Region III : \(E _{ x }= E _0 \sin kz\)
Region IV : \(E _{ x }= E _0 \cos kz\)
The displacement current will exist in the region :
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The energy associated with a cylindrical region due to an EM wave \(E=100 \sin (k x-\omega t)\) is \(u_0\). Find the equation of EM wave for which a cylinder of same length and half the diameter (as previous one) contains same energy \(u_0\).(Shift - I Memory Based)
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A point light source emits E.M. waves in free space. A detector, placed at a distance of L m , measures the intensity as \({I}_{0}\). The detector is now shifted to another location on the same spherical surface ensuring the angle between original location and new location as \(45^\circ\). The measured intensity at new location will be ____.
[JEE Main 2026, 6 Apr (Shift 1)]
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Arrange the following in the ascending order of wavelength \((\lambda )\) :
(A) Microwaves \(\left({\lambda }_{1}\right)\)
(B) Ultraviolet rays \(\left({\lambda }_{2}\right)\)
(C) Infrared rays \(\left({\lambda }_{3}\right)\)
(D) X-rays \(\left({\lambda }_{4}\right)\)
Choose the most appropriate answer from the options given below :
[JEE Main 2025, 24 Jan (Shift 2)]
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A plane electromagnetic wave propagates along the +x direction in free space. The components of the electric field, \(\vec{E}\) and magnetic field, \(\vec{B}\) vectors associated with the wave in Cartesian frame are;
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An electromagnetic wave travelling in x-direction is described by field equation \({E}_{y}=300\sin \omega \left(t-\frac{x}{c}\right)\). If the electron is restricted to move in y-direction only with speed of \(1.5\times {10}^{6}m/s\) then ratio of maximum electric and magnetic forces acting on the electron is
_________ .
[JEE Main 2026, 2 Apr (Shift 1)]
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An electromagnetic wave travels in free space along the x-direction. At a particular point in space and time, \(\vec{B}=2\times {10}^{-7}\hat{j}T\) is associated with this wave. The value of of corresponding electric field \(\vec{E}\) at this point is _________ V/m.
[02 April, 2026 (Shift-2)]
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Electromagnetic waves travel in a medium with speed of \(1.5\times {10}^{8}\mathrm{m}{\mathrm{s}}^{-1}\). The relative permeability of the medium is 2.0 . The relative permittivity will be:
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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 :
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Arrange the following in order of decreasing wavelength.
a: Microwave b: Ultraviolet
c: Infrared d: X-rays
(Shift II memory based)
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A monochromatic source of light operating at 15 kW emits \(2.5\times {10}^{22}\) photons/s. The region of an electromagnetic spectrum to which the emitted electromagnetic radiation belongs to _____________
(Take \(h=6.6\times {10}^{-34}J.s\) and \(c=3\times {10}^{8}m/s\) ).
[JEE Main 2026, 8 Apr (Shift 2)]
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If \({ϵ}_{0}\) denotes the permittivity of free space and \({\Phi }_{\mathrm{E}}\) is the flux of the electric field through the area bounded by the closed surface, then dimension of \(\left({\mathrm{ϵ}}_{0}\frac{{\mathrm{dϕ}}_{\mathrm{E}}}{\mathrm{dt}}\right)\) are that of :
[JEE Main 2025, 7 Apr (Shift 1)]
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A plane electromagnetic wave propagates along the +x direction in free space. The components of the electric field, \(\vec{E}\) and magnetic field, \(\vec{B}\) vectors associated with the wave in Cartesian frame are;
[JEE Main 2025, 29 Jan (Shift 2)]
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A parallel plate capacitor has a total plate area of \(16\text{ }{\text{cm}}^{2}\) and a distance of \(10\text{ }\text{cm}\) between the plates. This capacitor is connected to an AC source, and at a given instant, the current in the circuit is \(6\text{ }\text{A}\). Assuming a smaller region of area \(3.2\text{ }{\text{cm}}^{2}\) lies between and parallel to the plates, what is the displacement current in this region?
(Shift II Memory Based)
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The radiation pressure exerted by a \(450\mathrm{W}\) light source on a perfectly reflecting surface placed at \(2\)m away from it, is :
[JEE Main 2025, 3 Apr (Shift 1)]
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The electric field of an electromagnetic wave in free space is
\(\vec{\mathrm{E}}=57\cos \left[7.5\times {10}^{6}\mathrm{t}-5\times {10}^{-3}(3x+4y)\right](4\hat{i}-3\hat{j})N/C.\)
The associated magnetic field in Tesla is
[JEE Main 2025, 23 Jan (Shift 1)]
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In an electromagnetic wave, the magnetic field is given as \(\vec{B}=\left(\frac{\sqrt{3}}{2} \hat{\imath}+\frac{1}{2} \hat{\jmath}\right) 30 \sin (\omega t-k z)\), the corresponding electric field is
(Shift - II Memory Based)
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An electromagnetic wave propagates in the +X -direction. Then, the electric field and magnetic field are directed along
Options are free to see. Unlock the correct answer and full explanation with Pass.
The energy associated with a cylindrical region due to an EM wave \(E=100 \sin (k x-\omega t)\) is \(u_0\). Find the equation of EM wave for which a cylinder of same length and half the diameter (as previous one) contains same energy \(u_0\).(Shift - I Memory Based)
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Electric field of a plane electromagnetic wave propagating through a non-magnetic medium is given by \(\left(2\times {10}^{10}t-200x\right)\mathrm{V}/\mathrm{m}\). The dielectric constant of the medium is equal to: (Take \({\mu }_{r}=1\) )
[JEE Main 2021, 1 Sep (Shift 2)]
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An AC source is connected to a capacitor \(\mathrm{C}\). Due to decrease in its operating frequency:
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A travelling wave is described by the equation y(x, t) = [0.05 sin (8x – 4t)] m.
The velocity of the wave is [All the quantities are in SI unit]
[JEE Main 2023, 24 Jan (Shift 1)]
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Which of the following are true?
A. Speed of light in vacuum is dependent on the direction of propagation.
B. Speed of light in a medium is independent of the wavelength of light.
C. The speed of light is independent of the motion of the source.
D. The speed of light in a medium is independent of intensity.
Choose the correct answer from the options given below:
[JEE Main 2023, 29 Jan (Shift 1)]
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Which of the following Maxwell's equations is valid for time varying conditions but not valid for static conditions:
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If \(\vec{E}\) and \(\vec{K}\) represent electric field and propagation vectors of the EM waves in vacuum, then magnetic field vector is given by: ( \(\omega -\) angular frequency):
[JEE Main 2023, 24 Jan (Shift 1)]
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A linearly polarized electromagnetic wave in vacuum is \(E=3.1\cos \left[(1.8)z-\left(5.4\times {10}^{6}\right)t\right]\hat{i}N/C\) incident normally on a perfectly reflecting wall at \(z=a\). Choose the correct option
[JEE Main 2021, 25 Jul (Shift 1)]
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The electric field of a plane electromagnetic wave is given by \( \overrightarrow{\mathrm{E}}=\mathrm{E}_{0} \frac{\hat{\mathrm{i}}+\hat{\mathrm{j}}}{\sqrt{2}} \cos (k z+\omega \mathrm{t}) \). At \( \mathrm{t}=0 \), a positively charged particle is at the point \( (x, y, z)=\left(0,0, \frac{\pi}{k}\right) \). If its instantaneous velocity at \( (t=0) \) is \( v_{0} \hat{k} \), the force acting on it due to the wave is:
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The amplitude of magnetic field in an electromagnetic wave propagating along y-axis is \(6.0\times {10}^{-7}\mathrm{T}\). The maximum value of electric field in the electromagnetic wave is:
[JEE Main 2023, 10 Apr (Shift 2)]
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The electric field and magnetic field components of an electromagnetic wave going through vacuum is described by
\({E}_{x}={E}_{0}\sin (kz-\omega t)\)
\({B}_{y}={B}_{0}\sin (kz-\omega t)\)
Then the correct relation between \({E}_{0}\) and \({B}_{0}\) is given by
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For the plane electromagnetic wave given by \(E={E}_{0}\sin\) \((\omega t-kx)\) and \(B={B}_{0}\sin (\omega t-kx)\), the ratio of average electric energy density to average magnetic energy density is
[JEE Main 2023, 6 Apr (Shift 1)]
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An electron is constrained to move along the \( y \)-axis with a speed of \( 0.1 \mathrm{c} \) (c is the speed of light) in the presence of electromagnetic wave, whose electric field is \( \overrightarrow{\mathrm{E}}=30 \hat{\mathrm{j}} \sin \left(1.5 \times 10^{7} \mathrm{t}-5 \times 10^{-2} \mathrm{x}\right) \mathrm{V} / \mathrm{m} \). The maximum magnetic force experienced by the electron will be (Given \( \mathrm{c}=3 \times 10^{8} \mathrm{~ms}^{-1} \) and Electron charge \( = \) \( \left.1.6 \times 10^{-19} \mathrm{C}\right) \)
[JEE Main 2020, 5 Sep (Shift 1)]
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AC voltage \(V(t)=(20\sin \omega t)\)volt of frequency \(50\mathrm{Hz}\) is applied to a parallel plate capacitor. The separation between the plates is \(2\mathrm{mm}\) and the area is \(1{\mathrm{m}}^{2}\). The amplitude of the oscillating displacement current for the applied AC voltage is [ [Take \({\epsilon }_{0}=8.85\times {10}^{-12}\mathrm{F}/\mathrm{m}\) ]
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Given below are two statements:
Statement-I: Electromagnetic waves are not deflected by electric and magnetic field.
Statement-II: The amplitude of electric field and the magnetic field in electromagnetic waves are related to each other as \({E}_{0}=\sqrt{\frac{{\mu }_{0}}{{\epsilon }_{0}}}{B}_{0}\)
In the light of the above statements, choose the correct answer from the options given below:
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The energy density associated with electric field \(\vec{E}\) and magnetic field \(\vec{B}\) of an electromagnetic wave in free space is given by ( \(\epsilon_0\) - permittivity of free space, \(\mu_0\) - permeability of free space)
[JEE Main 2023, 6 Apr (Shift 2)]
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A point source of \(100\mathrm{W}\) emits light with 5% efficiency. At a distance of \(5\mathrm{m}\) from the source, the intensity produced by the electric field component is:
[JEE Main 2023, 30 Jan (Shift 2)]
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The magnetic field in a plane electromagnetic wave is given by \(B_y=2 \times 10^{-7} \sin \left(\pi \times 10^3 x+3 \pi \times 10^{11} t\right)\)T. Calculate the wavelength.
[NEET 2020]
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A plane electromagnetic wave of frequency \(20\mathrm{MHz}\) propagates in free space along x-direction. At a particular space and time, \(\vec{E}=6.6\hat{j}\mathrm{V}/\mathrm{m}\). What is \(\vec{B}\) at this point?
[JEE Main 2023, 11 Apr (Shift 2)]
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In an electromagnetic wave, at an instant and at a particular position, the electric field is along the negative Z-axis and magnetic field is along the positive x-axis. Then the direction of propagation of electromagnetic wave is :
[JEE Main 2023, 13 Apr (Shift 2)]
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The electric field of two plane electromagnetic waves in vacuum are given by \(\vec{E}=E_0 \cos (\omega t-k x) \hat{j}\) and \(\vec{E}_2=E_0 \cos (\omega t-k y) \hat{k}\). At \(t=0\), a particle of charge \(q\) is at origin with a velocity \(\vec{v}=0.8 c \hat{j}\). The instantaneous force experienced by the particle is
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The electric field and magnetic field components of an electromagnetic wave going through vacuum is described by
\({E}_{x}={E}_{o}\text{ }\sin \left(kz−\omega t\right)\)
\({B}_{y}={B}_{o}\text{ }\sin \left(kz−\omega t\right)\)
Then the correct relation \({E}_{o}\) and \({B}_{o}\) is given by
[JEE Main 2023, 24 Jan (Shift 2)]
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In \(\vec{E}\) and \(\vec{K}\) represent electric field and propagation vectors of the EM waves in vacuum, then magnetic field vector is given by:
(\(\omega\) - angular frequency):
[JEE Main 2023, 24 Jan (Shift 1)]
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Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: EM waves used for optical communication have longer wavelengths than that of microwave, employed in Radar technology.
Reason R: Infrared EM waves are more energetic than microwaves, (used in Radar)
In the light of given statements, choose the correct answer from the options given below:
[JEE Main 2023, 12 Apr (Shift 1)]
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In an electromagnetic wave the electric field vector and magnetic field vector are given as \(\vec{E}={E}_{0}\hat{i}\) and \(\vec{B}={B}_{0}\hat{k}\) respectively. The direction of propagation of electromagnetic wave is along.
[JEE Main 2021, 20 Jul (Shift 2)]
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Statement-1: Electromagnetic waves carry both energy and momentum despite having no mass.
Statement 2: The rest mass of a photon is zero.
(Shift - I Memory Based)
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In a plane electromagnetic wave, the directions of electric field and magnetic field are represented by \(\hat{k}\) and \(2\hat{i}-2\hat{j}\) respectively. What is the unit vector along the direction of propagation of the wave?
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A linearly polarized electromagnetic wave in vacuum is \(E=3.1\cos \left[(1.8)z-\left(5.4\times {10}^{6}\right)t\right]\hat{i}N/C\) Is incident normally on a perfectly reflecting wall at z=a. Choose the correct option
[JEE Main 2021, 25 Jul (Shift 1)]
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Identify the correct statements from the following descriptions of various properties of electromagnetic waves.
(A) In a plane electromagnetic wave electric field and magnetic field must be perpendicular to each other and direction of propagation of wave should be along electric field or magnetic field.
(B) The energy in electromagnetic wave is divided equally between electric and magnetic fields.
(C) Both electric field and magnetic filed are parallel to each other and perpendicular to the direction of propagation of wave.
(D) The electric field, magnetic field and direction of propagation of wave must be perpendicular to each other.
(E) The ratio of amplitude of magnetic field to the amplitude of electric field is equal to speed of light.
Choose the most appropriate answer from the options given below:
[JEE Main 2022, 27 Jul (Shift 2)]
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The ratio of average electric energy density and total average energy density of electromagnetic wave is:
[JEE Main 2023, 1 Feb (Shift 2)]
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AC voltage \(V(t)=(20\sin \omega t)\)volt of frequency \(50\mathrm{Hz}\) is applied to a parallel plate capacitor. The separation between the plates is \(2\mathrm{mm}\) and the area is \(1{\mathrm{m}}^{2}\). The amplitude of the oscillating displacement current for the applied AC voltage is [Take \({\epsilon }_{0}=8.85\times {10}^{-12}\mathrm{F}/\mathrm{m}\)]
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In list I we are given names of electromagnetic waves, and in list II the source of their production. Match list I with list II to find out the correct option.
|
| List I (Electromagnetic wave) |
| List II (Source of their production) |
| (a) | Radio | (I) | Radioactive decay of the nucleus |
| (b) | Gamma rays | (II) | Rapid acceleration and decelerations of electrons in aerials |
| (c) | Infrared | (III) | Vibration of atoms and molecules |
|
|
| (IV) | Inner shell electrons in atoms moving from one energy level to a lower level |
[JEE Main 2023, 1 Feb (Shift 1)]
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A light beam is described by \(\mathrm{E}=800\sin \omega \left(t-\frac{x}{c}\right)\)V/m. An electron is allowed to move normal to the propagation of light beam with a speed of \(3\times {10}^{7}{\mathrm{ms}}^{-1}\). What is the maximum magnetic force exerted on the electron?
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All electromagnetic wave is transporting energy in the negative z direction. At a certain point and certain time the direction of electric field of the wave is along positive y direction. What will be the direction of the magnetic field of the wave at that point and at that instant?
[JEE Main 2023, 25 Jan (Shift 1)]
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Given below are two statements:
Statement-I: Electromagnetic waves are not deflected by electric and magnetic field.
Statement-II: The amplitude of electric field and the magnetic field in electromagnetic waves are related to each other as
\({E}_{0}=\sqrt{\frac{{\mu }_{0}}{{\epsilon }_{0}}}{B}_{0}\)
In the light of the above statements, choose the correct answer from the options given below:
[JEE Main 2023, 29 Jan (Shift 2)]
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For the plane electromagnetic wave given by \(E={E}_{0}\sin (\omega t-kx)\) and \(B={B}_{0}\sin (\omega t-kx)\). the ratio of average electric energy density to average magnetic energy density is
[JEE Main 2023, 6 Apr (Shift 1)]
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