Electromagnetic Waves · Physics · KCET
MCQ (Single Correct Answer)
Electromagnetic waves are incident normally on a perfectly reflecting surface having surface area $A$. If $I$ is the intensity of the incident electromagnetic radiation and $c$ is the speed of light in vacuum, the force exerted by the electromagnetic wave on the reflecting surface is
The ratio of the magnitudes of electric field to the magnetic field of an electromagnetic wave is of the order of
Which of the following radiations of electromagnetic waves has the highest wavelength ?
Suppose that the electric field amplitude of electromagnetic wave is $$E_0=120 \mathrm{~NC}^{-1}$$ and its frequency $$f=50 \mathrm{~MHz}$$. Then, which of the following value is incorrectly computed?
The source of electromagnetic wave can be a charge
A light beam of intensity $$20 \mathrm{~W} / \mathrm{cm}^2$$ is incident normally on a perfectly reflecting surface of sides $$25 \mathrm{~cm} \times 15 \mathrm{~cm}$$. The momentum imparted to the surface by the light per second is
An antenna uses electromagnetic waves of frequency $$5 \mathrm{~MHz}$$. For proper working, the size of the antenna should be
Due to Doppler's effect the shift in wavelength observed is $$0.1 \mathop A\limits^o$$ for a star producing wavelength $$6000 \mathop A\limits^o$$. Velocity of recession of the star will be
An electromagnetic wave is travelling in $$x$$-direction with electric field vector given by, $$\mathbf{E}_y=E_0 \sin (k x-\omega t) \hat{\mathbf{j}}$$. The correct expression for magnetic field vector is
The phenomenon involved in the reflection of radio-waves by ionosphere is similar to