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An electromagnetic wave going through vaccum is described by $ E= E_o sin (kx - \omega t ) $ Which of the following is independent of the wavelength?
Which of the following have zero average value in a plane electromagnetic wave?
In a plane electromagnetic wave, the electric field and magnetic field oscillate sinusoidally with time. The average value of a sinusoidal function over a complete cycle is zero. Therefore, the average value of the electric field ( extbf{E}) in a plane electromagnetic wave is zero.
If the relative permeability and dielectric constant of a given medium are equal to $ l_r \,and K $ respectively, then the refractive index of the medium is equal to__________
The refractive index \( n \) of a medium is given by the square root of the product of its relative permeability \( \mu_r \) and dielectric constant \( \kappa \). Mathematically, \( n = \sqrt{\mu_r \kappa} \). Hence, the correct option is \( \sqrt{\mu_r \kappa} \).
Astraonomers have found that electromagnetic waves of wavelength 21cm are continuously reaching the Earth’s surface . Calculate the frequency of this radia- tion $ ( c = 3 \times 10^8 m/s) $
To find the frequency \( f \) of the radiation, we use the relation \( c = \lambda f \), where \( c \) is the speed of light, \( \lambda \) is the wavelength, and \( f \) is the frequency. Given \( \lambda = 21 \text{ cm} = 0.21 \text{ m} \) and \( c = 3 \times 10^8 \text{ m/s} \), we can calculate the frequency as: \[ f = \frac{c}{\lambda} = \frac{3 \times 10^8}{0.21} = 1.428 \times 10^9 \text{ Hz} = 1.428 \text{ GHz} \] Hence, the correct option is 1.428 GHz.
Electric field in an electromagnetic wave is given by $ E = 50 sin \omega ( t - (x/c )) NC^{-1} $ intensity of this wave is ___________ $Wm^-2$
The amplitude of the electric field in a parallel beam of light of intensity $ 2.0 Wm-^2$ is
Speed of electromagnetic wave is the same
The maximum electric field in a plane electromagnetic wave is $ 900 NC^{-1}$ . The wave is going in the x direction and the electric field is in the y direction. The maxi- mum magnetic field in the wave is ………….T
The relationship between the electric field (E) and the magnetic field (B) in an electromagnetic wave is given by:
$$ B = rac{E}{c} $$
Given, E = $900 ext{ NC}^{-1}$ and c = $3 imes 10^8 ext{ m/s}$, we can calculate the magnetic field (B) as:
$$ B = rac{900}{3 imes 10^8} = 3 imes 10^{-6} ext{ T} $$
Hence, the correct option is $3 imes 10^{-6} ext{ T}$.
Electromagnetic waves are produced by
Electromagnetic waves are produced by an accelerating charge. When a charge accelerates, it creates a changing electric field, which in turn creates a changing magnetic field, leading to the production of electromagnetic waves. This is a fundamental concept in electromagnetism.
 Maxwells equations are derived from the laws of___________
Maxwell's equations are derived from the laws of both electricity and magnetism. These four equations describe how electric fields and magnetic fields interact and propagate. They are crucial for understanding classical electromagnetism.
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