Electromagnetic Waves

JEE Main level, single correct, medium

79 of 165

Question 79 of 165

Intensity of sunlight is observed as 0.092Wm−20.092{Wm}^{-2} at a point in free space. What will be the peak value of magnetic field at that point ? (ϵ0=8.85×10−12C2N−1m−2)\left({\epsilon }_{0}=8.85\times {10}^{-12}{C}^{2}{N}^{-1}{m}^{-2}\right)

Show answer and solution

Answer: (A) 2.77×10−8T2.77\times {10}^{-8}T

{I}_{avg}=\dfrac{{B}_{0}^{2}C}{2{\mu }_{0}}&\dfrac{1}{{\mu }_{0}}={ϵ}_{0}{C}^{2}
I=B022ϵ0C3I=\dfrac{{B}_{0}^{2}}{2}{ϵ}_{0}{C}^{3}
B0=2Iϵ0C3{B}_{0}=\sqrt{\dfrac{2I}{{ϵ}_{0}{C}^{3}}}
B0=2.77×10−8T{B}_{0}=2.77\times {10}^{-8}T

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.

More Physics practice

JEE Main Physics practice question on Electromagnetic Waves (Electromagnetic Waves and Maxwell's equations), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.