Radiations from the sun fall on a prism and suffer dispersion. Three thermometers are kept on which the radiations after dispersion are made to fall as shown in the figure given below. Which thermometer would show a higher reading ? Give a reason for your answer.

Thermometer A (with red light) would show a higher reading.

Reason — Red light has the longest wavelength and the lowest frequency among the three. Hence, it carries more heat energy compared to violet or indigo light. As a result, it causes a greater rise in temperature, making thermometer A show a higher reading.