STANDARD Physics Electromagnetic Waves Class 12 Questions

Displacement current goes through the gap between the plates of a capacitor when the charge on the capacitor

The charge on a parallel plate capacitor varies as q = q₀ cos 2πνt. The plates are very large and close together (area = A, separation = d). The displacement current through the capacitor is

The conduction current is same as displacement current when source is

Which one among the following does not represent Maxwell's equation?

An electromagnetic wave can be produced, when charge is

Electromagnetic wave consists of periodically oscillating electric and magnetic vectors

The electric field associated with an electromagnetic wave in vacuum is given by E = 40cos(kz - 6 × 10⁸t) V/m, where E, z and t are in volt per metre, metre and second respectively. The value of wave vector k is

A radio can tune to any station in 7.5 MHz to 12 MHz band. The corresponding wavelength band is

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

Which of the following has/have zero average value in a plane electromagnetic wave?

A plane electromagnetic wave propagating along x direction can have the following pairs of E and B.

An electromagnetic wave of frequency ν = 3 MHz passes from vacuum into a dielectric medium with permittivity ε = 4. Then

If E and B denote electric and magnetic fields respectively, which of the following is dimensionless?

An electromagnetic wave propagating along north has its electric field vector upwards. Its magnetic field vector point towards

Which one of the following is the property of a monochromatic, plane electromagnetic wave in free space?

A solenoid of length 0.6 m has a radius of 2 cm and is made up of 600 turns. If it carries a current of 4 A, then the magnitude of the magnetic field inside the solenoid is

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

A solenoid of length 50 cm, having 100 turns carries a current of 2.5 A. The magnetic field at one end of the solenoid is

A plane electromagnetic wave travels in free space along X-direction. If the value of B (in tesla) at a particular point in space and time is 1.2 × 10⁻⁸ k̂, the value of E (in V m⁻¹) at that point is

A plane electromagnetic wave of frequency 25 MHz travels in free space along x-direction. At a particular point in space and time, electric field E = 6.3 V m⁻¹. The magnitude of magnetic field B at this point is

Which of the following is not true for electromagnetic waves?

The net magnetic flux through any closed surface, kept in a magnetic field is

The electric field part of an electromagnetic wave in vacuum is E = 3.1 N C⁻¹ × cos [(1.8 rad m⁻¹) y + (5.4 × 10⁸ rad s⁻¹) t]. The wavelength of this part of electromagnetic wave is

In the previous question, the frequency corresponding to the given part of electromagnetic wave is

In the previous question, the amplitude of magnetic field part of the given wave is

The electric field part of an electromagnetic wave in a medium is represented by Eₓ = 0, Eᵧ = -2.5 N/C cos [(2π × 10⁶ rad/m) t - (π × 10² rad/s) x], E_z = 0. The wave is

An electromagnetic wave of intensity I falls on a surface kept in vacuum and exerts radiation pressure P on it. Which of the following statement is not true?

A plane electromagnetic wave is incident on a material surface, the wave delivers momentum p and energy E, then

Light with an energy flux of 18 W cm⁻² falls on a non-reflecting surface at normal incidence. If the surface has an area of 20 cm², the average force exerted on the surface during a 30 minute time span is

In a moving coil galvanometer the deflection (ϕ) on the scale by a pointer attached to the spring is

The rms value of the electric field of the light coming from the sun is 720 N C⁻¹. The average total energy density of the electromagnetic wave is

A plane electromagnetic wave with electric field of amplitude 4 V m⁻¹ varies with time propagating along z-axis. The average energy density of the magnetic field (in J m⁻³) is

Which of the following electromagnetic wave play an important role in maintaining the earth’s warmth or average temperature through the greenhouse effect?

Which of the following electromagnetic wave is used in high precision application like LASIK eye surgery?

Which of the following electromagnetic waves has smallest wavelength?

The equivalent inductance of two inductors is 2.4 H when connected in parallel and 10 H when connected in series. What is the value of inductances of the individual inductors?

X-rays, gamma rays and microwaves travelling in vacuum have

A 100 mH coil carries a current of 1 A. Energy stored in its magnetic field is

An AC source is connected to a capacitor C. Due to decrease in its operating frequency:

A parallel plate condenser of capacity 100 pF is connected to 230 V of AC supply of 300 rad s⁻¹ frequency. The rms value of displacement current.

One requires 11 eV of energy to dissociate a carbon monoxide molecule into carbon and oxygen atoms. The minimum frequency of the appropriate electromagnetic radiation to achieve the dissociation lies in

Light with an energy flux of 20 W/cm² falls on a non-reflecting surface at normal incidence. If the surface has an area of 30 cm², the total momentum delivered (for complete absorption) during 30 minutes is

The part of the electromagnetic spectrum which is suitable for radar systems used in aircraft navigation.

The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is

A charged particle would continue to move with a constant velocity in a region wherein, which of the following conditions is not correct?

A parallel plate capacitor of capacitance 20 μF is being charged by a voltage source whose potential is changing at the rate of 3 V/s. The conduction current through the connecting wires, and the displacement current through the plates of the capacitor, would be, respectively

For a transparent medium relative permeability and permittivity, μᵣ and εᵣ are 1.0 and 1.44 respectively. The velocity of light in this medium would be

The energy associated with electric field is (Uₑ) and with magnetic field is (Uᵦ) for an electromagnetic wave in free space. Then

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

The magnetic field of an electromagnetic wave is given by \( \mathbf{B} = 1.6 \times 10^{-6} \cdot \cos(2 \times 10^7 z + 6 \times 10^{13} t) (2\mathbf{i} + \mathbf{j}) \frac{\text{Wb}}{\text{m}^2} \). The associated electric field will be