Sun light falls normally on a surface of area 36cm2 and exerts an average force of 7.2 × 10-9N within a time period of 20 minutes. Considering a case of complete adsorption, the energy flux of incident light is

A = 36 cm2= 36 × 104 m2? F? =7.2×10−9N, t=20min.? F? =ΔPΔt=ECΔt⇒EΔt=? F? c⇒EAΔt=? F? cA= 0.06 W/cm2

Sun light falls normally on a surface of area 36cm2 and exerts an average force of 7.2 × 10-9N within a time period of 20 minutes. Considering a case of complete adsorption, the energy flux of incident light is

25.92 × 102 W/cm2

8.64 × 10-6 W/cm2

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Physics Class 12th Electromagnetic Waves Physics NCERT Exemplar Solutions Class 12th Chapter Eight

Sun light falls normally on a surface of area 36cm² and exerts an average force of 7.2 × 10^-⁹N within a time period of 20 minutes. Considering a case of complete adsorption, the energy flux of incident light is

Option 1 -

25.92 * 10² W/cm²

Option 2 -

8.64 * 10^-6 W/cm²

Option 3 -

6.0 W/cm²

Option 4 -

0.06 W/cm²

2 Views | Posted 2 months ago

Asked by Shiksha User

1 Answer

Answered by

Vishal Baghel | Contributor-Level 10

2 months ago

Correct Option - 4

Detailed Solution:

A = 36 cm²= 36 × 104 m²

$? F ? = 7.2 \times 1 0^{- 9} N, t = 20 m i n .$

$? F ? = \frac{Δ P}{Δ t} = \frac{E}{C Δ t} \Rightarrow \frac{E}{Δ t} = ? F ? c \Rightarrow \frac{E}{A Δ t} = \frac{? F ? c}{A}$

= 0.06 W/cm²

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Sun light falls normally on a surface of area 36cm² and exerts an average force of 7.2 × 10^-⁹N within a time period of 20 minutes. Considering a case of complete adsorption, the energy flux of incident light is

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