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Physics Ncert Solutions Class 12th Physics Class 12th Electromagnetic Waves

8.4 A plane electromagnetic wave travels in vacuum along z-direction. What can you say about the directions of its electric and magnetic field vectors? If the frequency of the wave is 30 MHz, what is its wavelength?

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Payal Gupta | Contributor-Level 10

3 months ago

8.4 The electromagnetic wave travels in a vacuum along the z- direction. The electric field (E) and the magnetic field (H) are in the x-y plane. They are mutually perpendicular.

Frequency of the wave, $ν$ = 30 MHz = 30 $\times 10^{6}$ /s

Speed of light in vacuum, c = 3 $\times 10^{8}$ m/s

Wavelength of a wave is given as

$λ = \frac{c}{ν}$ = $\frac{3 \times 10^{8}}{30 \times 10^{6}}$ = 10 m

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8.4 A plane electromagnetic wave travels in vacuum along z-direction. What can you say about the directions of its electric and magnetic field vectors? If the frequency of the wave is 30 MHz, what is its wavelength?

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