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?

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

What is Luminiferous aether?

Why was the ether medium known as a hypothetical medium?

How was ether disproved?

According to ether hypothesis, which waves were not possible in gases or liquids?

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

Wavelength of electromagnetic wave $\mathrm{\beta }=8\times {10}^{-6} \sin \left(2\times {10}^{11}\mathrm{t}+300\mathrm{\pi x}\right)$ Tesla.

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 average force exerted on the surface is directly proportional to the total momentum delivered to that surface for complete absorption.

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 average force exerted on the surface during $30 \min$ time span.

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.

If the average force $2.5\times {10}^{-6}\mathrm{N}$ is exerted by a light wave on the non-reflecting surface of $30{\mathrm{cm}}^2$ area during $40\min$ time span, the energy flux of light just before it falls on the surface is _____$\mathrm{W}/{\mathrm{cm}}^2$.

When an electromagnetic wave falls on the surface it exerts ---------- on the surface.

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 $N$.