Electromagnetic Waves PYQs

Match List-I with List-II: Choose the correct answer from the options given below:

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

A parallel plate capacitor made of circular plates is being charged such that the surface charge density on its plates is increasing at a constant rate with time. The magnetic field arising due to displacement current is :

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 2.0 × 10¹⁰ Hz and amplitude 48 V m⁻¹. Then the amplitude of oscillating magnetic field is : (Speed of light in free space = 3 × 10⁸ m s⁻¹)

Match List-I with List-II. Choose the correct answer from the options given below

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)

The energy that will be ideally radiated by a 100 kW transmitter in 1 hour is:

A capacitor of capacitance $C$ is connected across an AC source of voltage $V$, given by $$V = V_0 \sin \omega t$$ The displacement current between the plates of the capacitor would then be given by:

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

A particular station of All India Radio, New Delhi broadcasts on a frequency of 1368 kHz. The wavelength of the electromagnetic radiation emitted by the transmitter is (speed of light c = $3.0 × 10^8 ms^-1)$:

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

Light with an average flux of 20 W/cm$^{2}$ falls on a non-reflecting surface at normal incidence having surface area 20 cm$^2$. The energy received by the surface during time span of 1 minute is:

For a transparent medium, relative permeability $\mu_r$ and permittivity $\varepsilon_r$ are $1.0$ and $1.44$ respectively. The velocity of light in this medium would be:

An electromagnetic wave is propagating in a medium with a velocity $\vec{V} = V\hat{i}$. The instantaneous oscillating electric field of this wave is along +y axis. Then the direction of oscillating magnetic field of the electromagnetic wave will be along:

The power radiated by a black body is P and it radiates maximum energy at wavelength $\lambda_0$. If the temperature of the black body is now changed so that it radiates maximum energy at wavelength (3/4)${\lambda_0}$, the power radiated by it becomes nP. The value of n is:

In an electromagnetic wave in free space, the root mean square value of electric field is $E_{\text{rms}} = 6\,\text{V/m}$. The peak value of magnetic field is:

A spherical black body with a radius of $12\,\text{cm}$ radiates $450\,\text{W}$ power at $500\,\text{K}$. If the radius were halved and the temperature doubled, the power radiated in watt would be:

A $100\ \Omega$ resistance and a capacitor of reactance $100\ \Omega$ are connected in series across 220 V source. When the capacitor is 50% charged, peak value of the displacement current is:

The energy of the electromagnetic waves is of the order of $15\,\text{keV}$. To which part of the electromagnetic spectrum does it belong?

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 propagating in vacuum is equal to:

"Good ozone" is found in the:

The electric field of an electromagnetic wave in free space is given by $\vec{E} = 10\cos(10^7 t + kx)\hat{j}\ \text{V/m}$, where t and x are in seconds and metres respectively. It can be inferred that: (i) the wavelength λ is 188.4 m (ii) the wave number k is 0.33 rad/m (iii) the wave amplitude is 10 V/m (iv) the wave is propagating along +x direction. Which one of the following pairs of statements is correct?

The electric field part of an electromagnetic wave in a medium is represented by: $$E_x=0$$ $$E_y=2.5\,\frac{N}{C}\cos\left[\left(2\pi\times10^6\,\frac{rad}{m}\right)t-\left(\pi\times10^{-2}\,\frac{rad}{s}\right)x\right]$$ $$E_z=0$$ The wave is:

The velocity of electromagnetic radiation in a medium of permittivity ε₀ and permeability μ₀ is given by

A black body at 1227°C emits radiations with maximum intensity at a wavelength of 5000 Å. If the temperature of the body is increased by 1000°C, the maximum intensity will be observed at:

If $\lambda_v$, $\lambda_x$ and $\lambda_m$ represent the wavelengths of visible light, X-rays and microwaves respectively, then: