Question

Two rays PQ and RS are incident on a rectangular glass block as shown in the diagram. Observe the diagram and answer the questions that follow.

Which of these two rays will:

1. have greater lateral displacement on emerging out of the block?
2. travel with greater speed in the block?
3. scatter more in the atmosphere?

Answer 1

1. Since ray RS is deviating more than ray PQ, the lateral displacement of RS will be greater.
2. Since the deviation of ray PQ is less than that of ray RS. So the ray PQ travels with greater speed.
3. Since RS has a smaller wavelength than PQ, the scattering of RS is more than that of PQ. (The fourth power of wavelength has an inverse relationship with scattering).