Physics - EM Waves Question with Solution | TestHub

PhysicsEM WavesElectromagnetic wavesEasy2 minPYQ_2020
PhysicsEasysingle choice

A laser beam of power 27 mW has a cross-sectional area of 10 mm2. The magnitude of the maximum electric field in this electromagnetic wave is given by

[Given permittivity of space ε09×10-12 C2 N-1 m-2, speed of light c=3×108 m s-1

Options:

Answer:
B
Solution:

I=PA=12ε0E02c

E0=2Pε0CA=2×27×10-3×36π×1093×108×10×10-6

E0=1.4 kV m-1

Subject:PhysicsTopic:EM WavesSubtopic:Electromagnetic waves
2mℹ️ Source: PYQ_2020

Doubts & Discussion

Loading discussions...