Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
Light with an energy flux of 25×104 W m-2 falls on a perfectly reflecting surface at normal incidence. If the surface area is 15 cm2, the average force exerted on the surface is:
PhysicsElectromagnetic WavesNEETNEET 2014
Options:
  • A 1.25×10-6N
  • B 2.50×10-6N
  • C 1.20×10-6N
  • D 3.0×10-6N
Solution:
2719 Upvotes Verified Answer
The correct answer is: 2.50×10-6N

Here, we have to calculate the average force calculated at the surface.

Given

I = 25×104

A = 15×10-4

We know that,

F=2IAC=225×10415×10-43×108=2.5×10-6N

Hence, force will be 2.5×10-6N

So Option (2) will be correct.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.