Sunlight of intensity 1.3   k W   m - 2 is incident normally on a thin convex lens of focal length 20   c m . Ignore the energy loss of light due to the lens and assume that the lens aperture size is much smaller than its focal length. The average intensity of light, in k W   m…

Question

Sunlight of intensity 1.3 &#160; k W &#160; m - 2 is incident normally on a thin convex lens of focal length 20 &#160; c m . Ignore the energy loss of light due to the lens and assume that the lens aperture size is much smaller than its focal length. The average intensity of light, in k W &#160; m - 2 , at a distance 22 &#160; c m from the lens on the other side is __________.

Aicharya · Accepted Answer

r R = 2 20 = 1 10 ∴ Ratio of area = 1 100 Let energy incident on lens be E ∴ Given E A = 1.3 E = A × 1.30 Also a A = 1 100 ∴ Average intensity of light at 22 c m = E a = A × 1.3 a = 100 × 1.3 = 130 k W / m 2 `

Sunlight of intensity 1.3   k W   m - 2 is incident normally on a thin convex lens of focal length…

Solution

Sunlight of intensity 1.3 &#160; k W &#160; m - 2 is incident normally on a thin convex lens of focal length…

Solution

Sunlight of intensity 1.3 k W m - 2 is incident normally on a thin convex lens of focal length…