A thin lens has a focal length of 10.00 cm for red light.If the index of refraction for the lens material tends to decrease with increasing wavelength,what is the focal length of the lens for blue light?
A)also 10.00 cm
B)less that 10.00 cm
C)more than 10.00 cm
D)It depends on whether the lens is converging or diverging.

Question

Quizplus · Accepted Answer

Since the index of refraction decreases with increasing wavelength, blue light will have a higher refractive index than red light. This means that blue light will be refracted more than red light, causing the focal length of the lens to be shorter for blue light. Therefore, the focal length of the lens for blue light will be less than 10.00 cm.

A Thin Lens Has a Focal Length of 10