ExamBro
ExamBro
JEE Mains · Physics · STD 12 - Electromagnetic waves
  • JEE Mains 2022
  • Medium
  • MCQ

Sun light falls normally on a surface of area \(36\,cm ^{2}\) and exerts an average force of \(7.2 \times 10^{-9}\,N\) within a time period of \(20\) minutes. Considering a case of complete absorption, the energy flux of incident light is.

Pick an option to check your answer.
Verified Solution

Answer & Solution

Correct Answer

(D) \(0.06\,W / cm ^{2}\)

Step-by-step Solution

Detailed explanation

\(\frac{I}{C} \times\) area \(=\) force

\(\frac{I}{C} \times 36 \times 10^{-4}=7.2 \times 10^{-9}\)

\(I =\frac{7.2 \times 10^{-9} \times 3 \times 10^{8}}{36 \times 10^{-9} \times 10}\)

\(=\frac{6 \times 10^{-1}}{10^{-3}}\)

\(I =6 \times 10^{2} \frac{ w }{ m ^{2}}\)

\(=0.06 \frac{ w }{ cm ^{2}}\)

Same subject
Explore more questions on app