When a light source is kept at a distance of 50 cm from a photocell, the stopping potentialvalue is recorded as 0.5 V.If the distance between the light source and the photocell increases upto 80 cm, then thevalue of stopping potential will be

Explanation

The stopping potential in a photocell is related to the intensity of light falling on it. As the distance between the light source and the photocell increases, the intensity of light decreases due to the inverse square law of light. This results in a decrease in stopping potential. Therefore, when the distance increases from 50 cm to 80 cm, the stopping potential decreases from 0.5 V to 0.25 V. Option A is correct because it reflects this decrease in stopping potential. Option B is incorrect because it assumes no change in stopping potential despite the increase in distance. Options C and D are incorrect as they suggest an increase in stopping potential, which contradicts the relationship between distance, intensity, and stopping potential in a photocell.