Electromagnetic Waves

An electromagnetic wave travelling in a lossless dielectric medium having a dielectric constant, $\varepsilon_r=9$, has the electric field, $E_x=E_0 \sin \left(k z-2 \pi \times 10^6 t\right) \vee m^{-1}$ where $E_0$ is the amplitude and $k$...

The following table presents the part of the electromagnetic spectrum and their corresponding major applications.








Part of the electromagnetic spectrum



Applications





P.

Microwave

I.

For purifying the water





Q.

UV rays
...

\(\text { Match List I with List II: }\)


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The electric field in a plane electromagnetic wave is given by \(E_z=60 \cos \left(5 x+1.5 \times 10^9 t\right) \mathrm{V} / \mathrm{m}\) Then expression for the corresponding magnetic field is (here subscripts denote the direction of the ...

If the ratio of relative permeability and relative permittivity of a uniform medium is \(1: 4\). The ratio of the magnitudes of electric field intensity \((E)\) to the magnetic field intensity \((H)\) of an EM wave propagating in that mediu...

The electromagnetic radiation which has the smallest wavelength are

The property which is not of an electromagnetic wave travelling in free space is that:

In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of \(2.0 \times 10^{10} \mathrm{~Hz}\) and amplitude \(48 ~\mathrm{Vm}^{-1}\). Then the amplitude of oscillating m...

The ratio of the magnitude of the magnetic field and electric field intensity of a plane electromagnetic wave in free space of permeability \({\mu _0}\) and permittivity \({\varepsilon _0}\) is (Given that c - velocity) of light in free spa...

The magnetic field of a plane electromagnetic wave is given by \(\overrightarrow B = 3 \times {10^{ - 8}}\cos (1.6 \times {10^3}x + 48 \times {10^{10}}t)\widehat j\), then the associated electric field will be :

When light propagates through a material medium of relative permittivity \(\varepsilon\)r and relative permeability \(\mu\)r, the velocity of light, v is given by (c-velocity of light in vacuum)

Match List - I with List - II

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For a plane electromagnetic wave propagating in x-direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?

The ratio of contributions made by the electric field and magnetic field components to the intensity of and electromagnetic wave is : (c = speed of electromagnetic waves)

Which colour of the light has the longest wavelength?

An EM wave is propagating in a medium with
a velocity \(\overrightarrow v = v\widehat i\). The instantaneous
oscillating electric field of this em wave is
along +y axis. Then the direction of oscillating
magnetic field of the em wave will ...

In an electromagnetic wave in free space that root mean square value of the electric field is Erms = 6 V m\(-\)1. The peak value of the magnetic field is

Out of the following options which one can be used to produce a propagating electromagnetic wave ?

A radiation of energy 'E' falls normally on a perfectly reflecting surface. The momentum transferred to the surface is (C = Velocity of light)

The energy of the em waves is of the order of 15 keV. To which part of the spectrum does it belong ?

Light with an energy flux of 25 \(\times\) 104 W m\(-\)2 falls on a perfectly reflecting surface at normal incidence. If the surface area is 15 cm2, the average force exerted on the surface is

An electromagnetic wave of frequency \(\upsilon = 3.0\) MHz passes from vaccum into a dielectric medium with relative permittivity \({{\varepsilon _r}}\) = 4.0. Then

The condition under which a microwave oven heats up a food item containing water molecules most efficiently is

The electric field associated with an em wave in vacuum is given by
E = \(\widehat i\) 40 cos (kz \(-\) 6 \(\times\) 108 t) where E, z and t are in volt/m, meter and seconds respectively. The value of wave vector k is

The ratio of amplitude of magnetic field to the amplitude of electric field for an electromagnetic wave propagatting in vacuum is equal to

The electric and the magnetic field, associated with an e.m. wave, propagating along the +z-axis, can be represented by

The decreasing order of wavelength of infrared, microwave, ultraviolet and gamma rays is

Which of the following statement is false for the properties of electromagnetic waves ?

The electric field of an electromagnetic wave in free space is given by \(\overrightarrow E = 10\cos ({10^7}t + kx)\widehat j\,\,V/m,\) where t and x are in seconds and metres respectively. It can be inferred that
(1)  the wavelength $$\la...

The electric field part of an electromagnetic wave in a medium is represented by Ex = 0;
$${E_y} = 2.5{N \over C}\cos \left[ {\left( {2\pi \times {{10}^6}{{rad} \over m}} \right)t - \left( {\pi \times {{10}^{ - 2}}{{rad} \over s}} \right)...

The velocity of electromagnetic radiation in a medium of permittivity \(\varepsilon\)0 and permeability \(\mu\)0 is given by

The electric and magnetic field of an electromagnetic wave are

If \(\lambda\)v, \(\lambda\)x and \(\lambda\)m represent the wavelengths of visible light, X-rays and microwaves respectively, then

Which of the following rays are not electromagnetic waves ?

We consider the radiation emitted by the human body. Which one of the following statements is true?

What is the cause of Green house effect ?

The velocity of electromagnetic wave is parallel to

Biological inportance of ozone layer is

The frequency order for \(\gamma\)-rays (a), X-rays (b), UV rays (c) is