Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Electromagnetic Waves

Question:

The amplitude of electric field in a parallel beam of light of intensity 4 Wm−2 is

Options:

40.5 NC−1

45.5 NC−1

50.5 NC−1

55.5 NC−1

Correct Answer:

55.5 NC−1

Explanation:

$I=\frac{1}{2}ε_0E^2_0 c$

$or \, E_2 = \sqrt{\frac{2I}{ε_0c}}$

$=\sqrt{\frac{2×4}{(8.85×10^{-12})×(3×10^8)}}$

$ = 55.5 \, NC^{-1}$