AP EAMCET202421 May 2024Evening ShiftPhysicsElectromagnetic WavesActual
The rms value of the electric field of an electromagnetic wave emitted by a source is 660 NC ⁻¹ . The average energy density of the electromagnetic wave is
Options
- A1.75 10⁻⁶ ~J ~m ⁻³
- B2.75 10⁻⁶ ~J ~m ⁻³
- C4.85 10⁻⁶ ~J ~m ⁻³
- D3.85 10⁻⁶ ~J ~m ⁻³
Correct answer
D. 3.85 10⁻⁶ ~J ~m ⁻³
Step-by-step solution
aligned & E _ rms =660 NC ⁻¹ & E ₀= 2 E _ rms = 2 660 NC ⁻¹ & Average density, U _ av = 1 2 ₀ E ₀^2 & = 1 2 8.85 10⁻¹² ( 2 660)^2 & =3.85 10⁻⁶ ~J m ⁻³ aligned