Electromagnetic Waves · Physics · AP EAPCET
MCQ (Single Correct Answer)
If the magnetic field in a plane progressive wave is represented by the equation $B_y=2 \times 10^{-7} \sin \left(0.5 \times 10^3 x+1.5 \pi \times 10^{11} t\right) \mathrm{T}$, then the frequency of the wave is
(In the equation time $t$ is in second)
If $11 \%$ of the power of a 200 W bulb is converted to visible radiation, then the intensity of the light at a distance of 100 cm from the bulb is
If a 10 W bulb emits electromagnetic waves uniformly in all directions, then the intensity of light at a distance 0.5 m from the source is nearly
The layer of the atmosphere that reflects low frequency (LF) electromagnetic waves during day time only is
The oscillating electric and magnetic field vectors of an electromagnetic wave are along
The ratio of the magnitudes of the electric field and $10^8$ times the magnetic field of a plane electromagnetic wave is
If the rms value of the electric field of electromagnetic waves at a distance of 3 m from a point source is $3 \mathrm{NC}^{-1}$, then the power of the source is
The magnitude of the electric field of a plane electromagnetic wave travelling in free space is $E$. If $\mu_0$ and $\varepsilon_0$ are respectively permeability and permittivity of the free space, then the magnitude of magnetic field of the wave is
A plane electromagnetic wave of frequency 25 MHz propagates in vacuum along positive $x$-direction. At a particular point in space and time, if the electric field is $63 \hat{\mathrm{j}} \mathrm{Vm}^{-1}$, then the magnitude of the magnetic field of the wave at this point at the same time is
If the magnetic field inside a solenoid is $B$, then the magnetic energy stored in it per unit volume is ( $c=$ speed of light in vacuum and $\varepsilon_0$ is permittivity of free space)
In a plane electromagnetic wave, the magnetic field is given by $\mathbf{B}=3 \times 10^{-7} \sin \left(100 \pi x+10^{12} t\right) \mathrm{T}$, then the wavelength of the wave is
(In the equation $x$ is in metre and $t$ is in second)
The magnetic field in a plane electromagnetic wave is given as $$\mathbf{B}=\left(3 \times 10^{-7} \mathrm{~T}\right) \sin \left(3 \times 10^4 x+9 \times 10^{12} t\right) \hat{j}$$
The electric field of this wave is given as
Frequencies in the UHF range normally propagate by means of
A light of intensity $$12 \mathrm{Wm}^{-2}$$ incidents on a black surface of area $$4 \mathrm{~cm}^2$$. The radiation pressure on the surface is
The electric field $$(E)$$ and magnetic field $$(B)$$ of an electromagnetic wave passing through vacuum are given by
$$\begin{aligned} & E=E_0 \sin (k x-\omega t) \\ & B=B_0 \sin (k x-\omega t) \end{aligned}$$
Then the correct statement among the following is
A carrier wave is used to transmit a message signal. If the peak voltage of modulating signal and carrier signal are increased by $$1 \%$$ and $$3 \%$$ respectively, the modulation index is changed by
A plane electromagnetic wave travels in free space along $$Z$$-axis. At a particular point in space, the electric field along $$X$$-axis is $$8.7 \mathrm{~Vm}^{-1}$$. The magnetic field along $$Y$$-axis is
If the average power per unit area delivered by an electromagnetic wave is $$9240 \mathrm{~Wm}^{-2}$$. then the amplitude of the oscillating magnetic field in EM wave is
A beam of light with intensity $$10^{-3} \mathrm{~Nm}^{-2}$$ and cross-sectional area $$20 \mathrm{~cm}^2$$ is incident on a fully reflective surface at angle $$45^{\circ}$$. Then, the force exerted by the beam on the surface is
The maximum number of TV signals, that can be transmitted along a co-axial cable is
The electric and the magnetic fields associated with an electromagnetic wave propagating along the $$z$$-axis, can be represented by
The magnetic field of a plane electromagnetic wave is given by $$B=(400 \propto \mathrm{T})\sin \left[\left(4.0 \times 10^{15} \mathrm{~s}^{-1}\right)\left(t-\frac{x}{c}\right)\right]$$. Average energy density corresponding to the electric field is
In an amplitude modulated signal, the maximum amplitude is $$15 \mathrm{~V}$$ and minimum amplitude is $$5 \mathrm{~V}$$. The amplitude of modulating wave will be