Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETPhysicsElectromagnetic Waves

An electromagnetic wave of total intensity I is propagating in vacuum. If c is the speed of light in vacuum, the average energy density of the magnetic field component of this wave is:

Options

  1. AI c
  2. BI c^2
  3. C2I c
  4. DI 2c

Correct answer

D. I 2c

Step-by-step solution

The total intensity I of an electromagnetic wave is related to its total average energy density u by the equation: I = u c u = I c In an electromagnetic wave, the total energy is shared equally between the electric and magnetic fields. Thus, the average energy density of the magnetic field ( u_B ) is exactly half of the total average energy density. u_B = u 2 = I 2c Answer: I 2c

Practice Electromagnetic Waves on Quantrex Academy →

More from Electromagnetic Waves

A parallel-plate capacitor of 50 F contains a dielectric slab of constant ( k ) with the same dimensions. If a time-varying potential difference is applied at a rate of 50 V/s . Wh 2026An electromagnetic wave travelling in a lossless dielectric medium having a dielectric constant, _r=9 , has the electric field, E_x=E₀ (kz-2 10^6 t) Vm ⁻¹ where E₀ is the amplitude 2026Match List I with List II : List I (Electromagnetic wave) List II (Production) A. Microwave I. Electrons in atoms emit light when they move from a higher energy level to a lower en 2026The following table presents the part of the electromagnetic spectrum and their corresponding major applications. Part of the electromagnetic spectrum Applications P. Microwave I. 2026A 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 fiel 2025The electric field in a plane electromagnetic wave is given by E_z=60 (5 x +1.5 10^9 t ) V / m . Then expression for the corresponding magnetic field is (here subscripts denote the 2025A parallel plate capacitor is charged by connecting it to a battery through a resistor. If I is the current in the circuit, then in the gap between the plates: 2024The electromagnetic radiation which has the smallest wavelength are 2024 Full Electromagnetic Waves list All NEET PYQs