Question

An eye can detect \( 5 \times 10^4 \) photons per square meter per second of green light ( \( \lambda = 500 \, \text{nm} \)) while the ear can detect \( 10^{-12} \, \text{W/m}^2 \). The factor by which the eye is more sensitive as a power detector than ear is close to?

• A. 5
• B. 0
• C. 5
• D. 0.5

Hint:

The sensitivity of the eye can be compared to the ear using the ratio of photon detection to power detection.

Answer 1

The Correct Option is A

The sensitivity of the eye as a power detector can be compared to the ear using the ratio of the detected photons to the power the ear can detect. The factor by which the eye is more sensitive is found by dividing the intensity that the eye detects by the sensitivity of the ear.