MCQ (Single Correct Answer)
The magnetic field of a plane electromagnetic wave is given by $$\overrightarrow B = 3 \times {10^{ - 8}}\cos (1.6 \times {10^3}x + 48 \times {10^{10...
The ratio of the magnitude of the magnetic field and electric field intensity of a plane electromagnetic wave in free space of permeability $${\mu _0}...
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...
The ratio of contributions made by the electric field and magnetic field components to the intensity of and electromagnetic wave is : (c = speed of el...
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 wa...
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...
A 100 $$\Omega $$ resistance and a capacitor of 100 $$\Omega $$ reactance are connected in series across a 220 V source. When the capacitor is 50% cha...
Out of the following options which one can be used to produce a propagating electromagnetic wave ?
The energy of the em waves is of the order of 15 keV. To which part of the spectrum does it belong ?
A radiation of energy 'E' falls normally on a perfectly reflecting surface. The momentum transferred to the surface is (C = Velocity of light)
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,...
An electromagnetic wave of frequency $$\upsilon = 3.0$$ MHz passes from vaccum into a dielectric medium with relative permittivity $${{\varepsilon _r...
The condition under which a microwave oven heats up a food item containing water molecules most efficiently is
The ratio of amplitude of magnetic field to the amplitude of electric field for an electromagnetic wave propagatting in vacuum is equal to
The electric field associated with an em wave in vacuum is given by
E = $$\widehat i$$ 40 cos (kz $$-$$ 6 $$ \times $$ 108 t) where E, z and t are in...
The electric and the magnetic field, associated with an e.m. wave, propagating along the +z-axis, can be represented by
The decreasing order of wavelength of infrared, microwave, ultraviolet and gamma rays is
The electric field of an electromagnetic wave in free space is given by $$\overrightarrow E = 10\cos ({10^7}t + kx)\widehat j\,\,V/m,$$ where t and x...
Which of the following statement is false for the properties of electromagnetic waves ?
The electric field part of an electromagnetic wave in a medium is represented by Ex = 0;
$${E_y} = 2.5{N \over C}\cos \left[ {\left( {2\pi \times {{1...
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?
The velocity of electromagnetic wave is parallel to
What is the cause of Green house effect ?
Biological inportance of ozone layer is
The frequency order for $$\gamma $$-rays (a), X-rays (b), UV rays (c) is