NEET Physics Electromagnetic Waves Class 12 Questions

The magnetic energy stored in an inductor of inductance 4μH carrying a current of 2A is

The dimensions of magnetic flux are

Match List I with List II:

Beams of electrons and protons move parallel to each other in the same direction. They

If μ₀ = permeability of free space & ε₀ = permittivity of free space. Find the value of μ₀ε₀.

Identify the correct statements from the following descriptions of various properties of electromagnetic waves. A. In a plane electromagnetic wave electric field and magnetic field must be perpendicular to each other and direction of propagation of wave should be along electric field or magnetic field. B. The energy in electromagnetic wave is divided equally between electric and magnetic fields.

The energy density associated with electric field E̅ and magnetic field B̅ of an electromagnetic wave in free space is given by (ε₀ - permittivity of free space, μ₀ permeability of free space)

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

Lenz's law is consequence of the law of conservation of

A square of side L metres lies in the xy-plane in a region, where the magnetic field is given by B = B₀(2î + 3ĵ + 4k̂)T, where B₀ is constant. The magnitude of flux passing through the square is

A copper ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet while it is passing through the ring is

The self inductance L of a solenoid of length l and area of cross-section A, with a fixed number of turns N increases as

Point out the correct direction of magnetic field in the given figure.

If E and B represent electric and magnetic field vectors of the electromagnetic wave, the direction of propagation of electromagnetic wave is along

A 220 V ac supply is connected between points A and B as shown in figure. What will be the potential difference V across the capacitor?

Two batteries of emf \( \varepsilon_1 \) and \( \varepsilon_2 \) (\( \varepsilon_2 > \varepsilon_1 \)) and internal resistances \( r_1 \) and \( r_2 \) respectively are connected in parallel as shown in figure.

An electromagnetic wave can be produced, when charge is

The magnetic field of a plane electromagnetic wave is given by: B⃗ = 2×10⁻⁸ sin(0.5×10³x + 1.5×10¹¹t)ĵT. The amplitude of the electric field would be:

Which of the following will have the dimensions of time:

A laser beam has intensity of 4.0 × 10¹⁴ W/m². The amplitude of magnetic field associated with beam is _______. (Take ε₀ = 8.85 × 10⁻¹²C²/Nm² and c = 3 × 10⁸ m/s)

If electron is moving from A to B in wire AB, then current induced in the coil is

The electric field of an electromagnetic wave travelling through a medium is given by E(x,t) = 25sin(2.0×10⁻¹⁵t−10⁷x)k̂ then the refractive index of the medium is (All given measurement are in SI units)

Which of the following combinations has the dimension of electrical resistance (ε₀ is the permittivity of vacuum and μ₀ is the permeability of vacuum)?

Select the incorrect statement from the following:

Match List I with List II:

A bulb is rated at 150 watt, converting 8% energy into light. If energy of one photon is 4.42 × 10⁻¹⁹ J, how many photons are emitted by the bulb per second?

An electron (mass 9×10⁻³¹ kg and charge 1.6×10⁻¹⁹C) moving with speed c/100 (c = speed of light) is injected into a magnetic field B of magnitude 9×10⁻⁴ T perpendicular to its direction of motion. We wish to apply an uniform electric field E together with the magnetic field so that the electron does not deflect from its path. Then (speed of light c = 3×10⁸ ms⁻¹)

The electric field in a plane electromagnetic wave is given by Eₓ = 60cos (5x + 1.5×10⁹t)V/m. Then 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:

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

In a plane electromagnetic wave travelling in free space, the electric field component oscillates sinusoidally at a frequency of 2.0×10¹⁰ Hz and amplitude 48 Vm⁻¹. Then the amplitude of oscillating magnetic field is: (Speed of light in free space = 3 × 10⁸ m s⁻¹)

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

When light propagates through a material medium of relative permittivity εᵣ and relative permeability μᵣ, the velocity of light, v, is given by: (c-velocity of light in vacuum)

Match List – I with List – II

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

The number of photons per second on an average emitted by the source of monochromatic light of wavelength 600 nₘ, when it delivers the power of 3.3 × 10⁻³ watt will be : (h = 6.6 × 10⁻³⁴ Js)

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/cm² falls on a non-reflecting surface at normal incidence having surface area 20 cm². The energy received by the surface during time span of 1 minute is:

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

An em wave is propagating in a medium with a velocity v⃗ = vî. The instantaneous oscillating electric field of this em wave is along +Y axis. Then the direction of oscillating magnetic field of the em wave will be along

In an electromagnetic wave in free space the root mean square value of the electric field is Eₘₛ = 6 V/m. The peak value of the magnetic field is:

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

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 × 10⁴ Wm⁻² falls on a perfectly reflecting surface at normal incidence. If the surface area is 15 cm², the average force exerted on the surface is

An electromagnetic wave of frequency ν = 3.0 MHz passes from vacuum into a dielectric medium with relative permittivity ε = 4.0. Then: