Optics Question 179

Question: A lamp emits monochromatic green light uniformly in all directions. The lamp is 3% efficient in converting electrical power to electromagnetic waves and consumes 100W of power. The amplitude of the electric field associated with the electromagnetic radiation at a distance of 10m from the lamp will be

Options:

A) 1.34 V/m

B) 2.68 V/m

C) 5.36 V/m

D) 9.37 V/m

Show Answer

Answer:

Correct Answer: A

Solution:

Sav=12ε0cE02=P4πR2

Therefore E0=P2πR2ε0C

=32×3.14×100×8.85×1012×3×108 = 1.34 V/m



NCERT Chapter Video Solution

Dual Pane