Properties of Electromagnetic Waves PYQs: JEE Mains Physics

Showing 1–50 of 123 questions

1. 1. A laser beam has intensity of \( 4.0\times10^{14} W/m^{2} \). The amplitude of magnetic field associated with beam is__________ T. (Take \( \epsilon_{0}=8.85\times10^{-12} C^{2}/Nm^{2} \) and \( c=3\times10^{8} m/s \)) 2026 Easy
2. 2. A magnetic field vector in an electromagnetic wave is represented by \(\vec{B}=B_0\sin\left(2\pi vt-\dfrac{2\pi x}{\lambda}\right)\hat{j}\). Its associated electric field vector is ______. 2026 Medium
3. 3. A plane electromagnetic wave is moving in free space with velocity \(c =3 \times 10^8 m / s\) and its electric field is given as \(\overrightarrow{ E }=54 \sin ( kz -\omega t ) \hat{ j } V / m\), where \(\hat{j}\) is the unit vector along \(y\)-axis. The magnetic field vector \(\overrightarrow{ B }\) of the wave is : 2026 Hard
4. 4. A point light source emits E.M. waves in free space. A detector, placed at a distance of \(L\) m, measures the intensity as \(I_o\). The detector is now shifted to another location on the same spherical surface ensuring the angle between original location and new location as \(45°\). The measured intensity at new location will be _______. 2026 Easy
5. 5. An electromagnetic wave travelling in \(x\)-direction is described by field equation \(E_y = 300\sin\omega\left(t - \dfrac{x}{c}\right)\). 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 _______. 2026 Medium
6. 6. 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 : 2026 Medium
7. 7. Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
   Assertion (A): The electromagnetic wave exerts pressure on the surface on which they are allowed to fall.
   Reason (R): There is no mass associated with the electromagnetic waves.
   In the light of the above statements, choose the correct answer from the options given below : 2026 Medium
8. 8. Match the List-I with List-II
   

   	List-I		List-II
   A	Radio-wave	I	is produced by Magnetron value
   B	Micro-wave	II	Due to change in the vibrational modes of atoms
   C	Infrared-wave	II	Due to inner shell electrons moving from higher energy level to lower energy level
   D	X-ray	IV	Due to rapid acceleration of electrons

   Choose the correct answer from the options given below: 2026 Hard
9. 9. The dimensional formula of \(\dfrac{1}{2}\epsilon_0 E^2\) (\(\epsilon_0\) = permittivity of vacuum and \(E\) = electric field) is \(M^a L^b T^c\). The value of \(2a - b + c = \) _______. 2026 Medium
10. 10. The electric field a plane electromagnetic wave is given by :
    \(E _y=69 \sin \left[0.6 \times 10^3 x -1.8 \times 10^{11} t \right] V / m\).
    The expression for magnetic field associated with this electromagnetic wave is _________ T. 2026 Hard
11. 11. The electric field of a plane electromagnetic wave, travelling in an unknown non-magnetic medium is given by,
    \(E_y=20 \sin \left(3 \times 10^6 x-4.5 \times 10^{14} t\right) V / m\)
    (where \(x, t\) and other values have S.I. units). The dielectric constant of the medium is __________ .
    (speed of light in free space is \(3 \times 10^8 m / s\) ) 2026 Easy
12. 12. The electric field of an electromagnetic wave travelling through a medium is given by \(\overline{E}(x,t) = 25\ sin(2.0 \times 10^{15}t - 10^{7}x)\hat{n}\) then the refractive index of the medium is ___________.
    (All given measurement are in SI units) 2026 Hard
13. 13. The equation of the electric field of an electromagnetic wave propagating through free space is given by :
    E \(=\sqrt{377} \sin \left(6.27 \times 10^3 t -2.09 \times 10^{-5} x \right)\) N/C
    he average power of the electromagnetic wave is\(\left(\frac{1}{\alpha}\right) W / m ^2\). The value of \(\alpha\) is ___________
    \(\left(\right.\) Take \(\sqrt{\frac{\mu_0}{\varepsilon_0}}=377\) in SI units \()\) 2026 Medium
14. 14. The ratio of speeds of electromagnetic waves in vacuum and a medium, having dielectric constant k=3 and permeability \(\mu=2\mu_{0}\), is
    ( \(\mu_0=\) permeability of vacuum) 2026 Easy
15. 15. 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: 2025 Medium
16. 16. 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 2025 Easy
17. 17. Due to presence of an em-wave whose electric component is given by \(\mathrm{E}=100 \sin (\omega \mathrm{t}-\mathrm{kx}) \mathrm{NC}^{-1}\), 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 2025 Medium
18. 18. If an optical medium possesses a relative permeability of \(\frac{10}{\pi}\) and relative permittivity of \(\frac{1}{0.0885}\), then the velocity of light is greater in vacuum than that in this medium by ________ times.
    \(\left(\mu_0=4 \pi \times 10^{-7} \mathrm{H} / \mathrm{m}, \epsilon_0=8.85 \times 10^{-12} \mathrm{~F} / \mathrm{m}\right.\)
    \(\left.\mathrm{c}=3 \times 10^8 \mathrm{~m} / \mathrm{s}\right)\) 2025 Easy
19. 19. The electric field of an electromagnetic wave in free space is \(\overrightarrow{\mathrm{E}}=57 \cos \left[7.5 \times 10^6 \mathrm{t}-5 \times 10^{-3}(3 x+4 y)\right](4 \hat{i}-3 \hat{j}) N / C\). The associated magnetic field in Tesla is _______. 2025 Medium
20. 20. The magnetic field of an E.M. wave is given by \(\overrightarrow{\mathrm{B}}=\left(\frac{\sqrt{3}}{2} \hat{i}+\frac{1}{2} \hat{j}\right) 30 \sin \left[\omega\left(\mathrm{t}-\frac{z}{\mathrm{c}}\right)\right]\) (S.I. Units).
    The corresponding electric field in S.I. units is : 2025 Easy
21. 21. A plane electromagnetic wave of frequency \(35\  \mathrm{MHz}\) travels in free space along the \(\mathrm{X}\)-direction. At a particular point (in space and time) \(\overrightarrow{\mathrm{E}}=9.6\  \hat{\mathrm{j}} \mathrm{V} / \mathrm{m}\). The value of magnetic field at this point is _______. 2024 Hard
22. 22. A plane electromagnetic wave propagating in \(\mathrm{x}\)-direction is described by \(\mathrm{E}_{\mathrm{y}}=\left(200\  \mathrm{Vm}^{-1}\right) \sin \left[1.5 \times 10^7 \mathrm{t}-0.05\  \mathrm{x}\right] \text {; }\) The intensity of the wave is :(Use \(\epsilon_0=8.85 \times 10^{-12} \mathrm{C}^2 \mathrm{~N}^{-1} \mathrm{~m}^{-2}\) ) 2024 Hard
23. 23. A plane EM wave is propagating along \(\mathrm{x}\) direction. It has a wavelength of \(4 \mathrm{~mm}\). If electric field is in y direction with the maximum magnitude of \(60 \mathrm{Vm}^{-1}\), the equation for magnetic field is _______. 2024 Hard
24. 24. Electromagnetic waves travel in a medium with speed of \(1.5 \times 10^8 \mathrm{~ms}^{-1}\). The relative permeability of the medium is \(2.0\) . The relative permittivity will be _______. 2024 Hard
25. 25. Given below are two statements:
    Statement \(I\): Electromagnetic waves carry energy as they travel through space and this energy is equally shared by the electric and magnetic fields.
    Statement \(II\): When electromagnetic waves strike a surface, a pressure is exerted on the surface.
    In the light of the above statements, choose the most appropriate answer from the options given below: 2024 Hard
26. 26. If frequency of electromagnetic wave is \(60 \mathrm{MHz}\) and it travels in air along \(\mathrm{z}\) direction then the corresponding electric and magnetic field vectors will be mutually perpendicular to each other and the wavelength of the wave (in \(\mathrm{m}\) ) is _______. 2024 Hard
27. 27. In a plane \(EM\) wave, the electric field oscillates sinusoidally at a frequency of \(5 \times 10^{10} \mathrm{~Hz}\) and an amplitude of \(50 \mathrm{Vm}^{-1}\). The total average energy density of the electromagnetic field of the wave is _______. [Use \(\varepsilon_0=8.85 \times 10^{-12} \mathrm{C}^2 / \mathrm{Nm}^2\) ] 2024 Hard
28. 28. In the given electromagnetic wave \(E_y=600 \sin (\omega t-k x) \mathrm{Vm}^{-1}\), intensity of the associated light beam is what? (in \(\mathrm{W} / \mathrm{m}^2\) ); (Given \(\epsilon_0=\) \(\left.9 \times 10^{-12} \mathrm{C}^{-2} \mathrm{~N}^{-1} \mathrm{~m}^{-2}\right)\) 2024 Hard
29. 29. The electric field in an electromagnetic wave is given by \(\overrightarrow{\mathrm{E}}=\hat{\mathrm{i}} 40 \cos \omega\left(\mathrm{t}-\frac{\mathrm{z}}{\mathrm{c}}\right) N \mathrm{NC}^{-1}\). The magnetic field induction of this wave is (in SI unit) _______. 2024 Hard
30. 30. The electric field of an electromagnetic wave in free space is represented as \(\vec{E}=E_0 \cos (\omega t-k z) \hat{i}\). The corresponding magnetic induction vector will be _______. 2024 Hard
31. 31. The magnetic field in a plane electromagnetic wave is \(\mathrm{B}_y=\left(3.5 \times 10^{-7}\right) \sin \left(1.5 \times 10^3 \mathrm{x}+0.5\right.\) \(\left.\times 10^{11} \mathrm{t}\right) \mathrm{T}\). The corresponding electric field will be _______. 2024 Hard
32. 32. A plane electromagnetic wave of frequency \(20\,MHz\) propagates in free space along \(x\)-direction. At a particular space and time, \(\overrightarrow{ E }=6.6 \hat{ j } V / m\). What is \(\overrightarrow{ B }\) at this point? 2023 Medium
33. 33. A point source of \(100\,W\) emits light with \(5 \%\) efficiency. At a distance of \(5\,m\) from the source, the intensity produced by the electric field component is : 2023 Medium
34. 34. 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 instant? 2023 Easy
35. 35. For the plane electromagnetic wave given by \(\mathrm{E}=\mathrm{E}_0 \sin (\omega \mathrm{t}-\mathrm{kx})\) and \(\mathrm{B}=\mathrm{B}_0 \sin (\omega \mathrm{t}-\mathrm{kx})\), the ratio of average electric energy density to average magnetic energy density is 2023 Medium
36. 36. 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 \(E _0=\sqrt{\frac{\mu_0}{\varepsilon_0}} B_0\) In the light of the above statements, choose the correct answer from the options given below: 2023 Medium
37. 37. If a source of electromagnetic radiation having power \(15 kW\) produces \(10^{16}\) photons per second, the radiation belongs to a part of spectrum is.(Take Planck constant \(h =6 \times 10^{-34}\,Js\) ) 2023 Easy
38. 38. 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) : 2023 Medium
39. 39. 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 2023 Easy
40. 40. The amplitude of magnetic field in an electromagnetic wave propagating along \(y\)-axis is \(6.0 \times 10^{-7}\,T\). The maximum value of electric field in the electromagnetic wave is: 2023 Easy
41. 41. 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 2023 Medium
42. 42. The electric field in an electromagnetic wave is given as \(\vec{E}=20 \sin \omega\left(t-\frac{x}{c}\right) \vec{j} NC ^{-1}\) Where \(\omega\) and \(c\) are angular frequency and velocity of electromagnetic wave respectively. The energy contained in a volume of \(5 \times 10^{-4}\, m ^3\) will be \(.....\times 10^{-13}\,J\) (Given \(\varepsilon_0=8.85 \times 10^{-12}\,C ^2 / Nm ^2\) ) 2023 Medium
43. 43. The energy density associated with electric field \(\overrightarrow{ E }\) and magnetic field \(B\) of an electromagnetic wave in free space is given by ( \(\epsilon_0-\) permittivity of free space, \(\mu_0\) - permeability of free space) 2023 Medium
44. 44. The energy of an electromagnetic wave contained in a small volume oscillates with 2023 Medium
45. 45. The ratio of average electric energy density and total average energy density of electromagnetic wave is: 2023 Easy
46. 46. A beam of light travelling along \(X\)-axis is described by the electric field \(E _{ y }=900 \sin \omega( t - x / c )\). The ratio of electric force to magnetic force on a charge \(q\) moving along \(Y\)-axis with a speed of \(3 \times 10^{7}\,ms ^{-1}\) will be. [Given speed of light \(=3 \times 10^{8}\,ms ^{-1}\) ] 2022 Medium
47. 47. A plane electromagnetic wave travels in a medium of relative permeability \(1.61\) and relative permittivity \(6.44\). If magnitude of magnetic intensity is \(4.5 \times 10^{-2} \;Am ^{-1}\) at a point, what will be the approximate magnitude of electric field intensity at that point\(?\) (Given : permeability of free space \(\mu_{0}=4 \pi \times 10^{-7}\;NA ^{-2}\), speed of light in vacuum \(c =3 \times 10^{8} \;ms ^{-1}\) ) 2022 Medium
48. 48. A radar sends an electromagnetic signal of electric field \(\left( E _{0}\right)=2.25\,V / m\) and magnetic field \(\left( B _{0}\right)=1.5 \times 10^{-8}\,T\) which strikes a target on line of sight at a distance of \(3\,km\) in a medium After that, a pail of signal \((echo)\) reflects back towards the radar vitli same velocity and by same path. If the signal was transmitted at time \(t_{0}\) from radar. then after how much time (in  \(\times 10^{-5}\,s\)) echo will reach to the radar? 2022 Medium
49. 49. A velocity selector consists of electric field \(\overrightarrow{ E }= E \hat{ k }\) and magnetic field \(\overrightarrow{ B }= B \hat{ j }\) with \(B =12 mT\). The value \(E\) required for an electron of energy \(728 eV\) moving along the positive \(x\)-axis to pass undeflected is: (Given, , ass of electron \(=9.1 \times 10^{-31} kg\) ) 2022 Hard
50. 50. An antenna is placed in a dielectric medium of dielectric constant \(6.25\). If the maximum size of that antenna is \(5.0\, mm\). it can radiate a signal of minimum frequency of \(GHz .\) (Given \(\mu_{ r }=1\) for dielectric medium) 2022 Medium

No questions on this page match these filters. Clear filters