Nature of Electromagnetic Waves

An electromagnetic wave is travelling in a medium with a velocity $\overrightarrow{v}=v\widehat{i}$ . The electric field oscillations, of this electromagnetic wave wave, are along the y – axis.

(a) Identify the direction in which the magnetic field oscillations are taking place, of the electromagnetic wave wave.

(b) How are the magnitudes of the electric and magnetic fields in the electromagnetic wave related to each other?

Light with an energy flux of$25\times {10}^4{\mathrm{wm}}^{-2}$ falls on a perfectly reflecting surface at normal incidence. If the surface area is $15{\mathrm{cm}}^2$ , the average force exerted on the surface is

The electric field of a plane electromagnetic wave propagating along the z-axis varies with time with an amplitude of $2\mathrm{ }\mathrm{V} {\mathrm{m}}^{-1}$. The average energy density of the magnetic field (in $\mathrm{J}\mathrm{ }{\mathrm{m}}^{-3}$) is :

Take: ${\mathrm{\epsilon }}_0=8.854\times {10}^{-12} \mathrm{F} {\mathrm{m}}^{-1}$

Which experiment disapproves, the ether hypothesis

Mention the characteristics of ether.

What is 'ether '?

Electric field amplitude of electromagnetic wave is $240 {\mathrm{NC}}^{-1}$ and frequency $50 \mathrm{MHz}$, if the wave is propagating along $\mathrm{x}-\mathrm{axis}$ then equation of wave for electric field is

Magnitude of wave vector is reciprocal to wavelength and direction perpendicular to wavelength.

Electromagnetic waves propagating along $\mathrm{x}-\mathrm{axis}$, the equation for electric field along $\mathrm{y}-\mathrm{axis}$ is expressed as ${\mathrm{E}}_{\mathrm{y}}={\mathrm{E}}_0 \sin 2\mathrm{\pi }\left(\frac{\mathrm{x}}{\mathrm{\lambda }}-\frac{\mathrm{t}}{\mathrm{T}}\right)$, the wave vector is 

The light with an energy flux of $18\mathrm{W}/{\mathrm{cm}}^2$ falls on a non-reflecting surface at normal incidence. If the surface has an area of $20{\mathrm{cm}}^2$. Find the total momentum delivered on the surface during $30 \min$ time span.

The momentum of an electromagnetic wave is defined as the _____ carried by an electromagnetic wave divided by the speed of light.

When the sun shines on your hand, you feel the energy being absorbed from the electromagnetic wave.

Write the expression for the linear momentum delivered by the radiation for the complete absorption.

Name the physical quantity which is transports by the electromagnetic wave as it travels through space.

A tube of length $30 \mathrm{cm}$ has its inner lateral surface blackened. Two lenses of focal lengths $10 \mathrm{cm}$ and $20 \mathrm{cm}$ are fixed at the ends of the tube. For same beam, intensities of spots on screen are $I_1$ and $I_2$ for arrangement $\left(1\right)$ and arrangement $\left(2\right)$. If the ratio of $I_2 : I_1$ is of the form $N^2\text{,}$ find $N$.

Calculate the amplitude of electric field (in $\mathrm{N} {\mathrm{C}}^{-1}$) in a parallel beam of light of intensity $4 \mathrm{W} {\mathrm{m}}^{-2}$.

Which of the following pairs of space and time-varying $E$ and $B$ fields would generate a plane electromagnetic wave travelling in the $(+x)$ direction?

Wavelength of EM waves varies from ______ to ________

The peak electric field produced by the radiation coming from the $8 \mathrm{W}$ bulb at a distance of $10 \mathrm{m}$ is $\frac{\mathrm{x}}{10}\sqrt{\frac{{\mathrm{\mu }}_0\mathrm{C}}{\mathrm{\pi }}}\frac{\mathrm{V}}{\mathrm{m}}$. The efficiency of the bulb is $10\%$ and it is a point source. The value of $\mathrm{x}$ is _____.

An electromagnetic wave of frequency $3 \mathrm{GHz}$ enters a dielectric medium of relative electric permittivity $2.25$ from vacuum. The wavelength of this wave in that medium will be $\frac{100}{n} \mathrm{cm}$. Write the value of $n$. (Take ${\mu }_r=1$)