A beam consisting of red, blue and yellow colours is incident normally on the face AB of an isosceles right-angled prism ABC as shown in the figure given below. Critical angle of glass-air interface for yellow colour is 45°.

Out of the four emergent rays P, Q, R and S, which one is for the yellow colour :

1. P
2. Q
3. R
4. S

The frequency of violet light is 7.5 x 10¹⁴ Hz. Its wavelength in nm is :

1. 7500 nm
2. 4000 nm
3. 400 nm
4. 750 nm

Assertion (A): When a ray of light is refracted through a rectangular glass slab, there is no dispersion of light.

Reason (R): Dispersion of light is the phenomenon of splitting of white light into its constituent colours.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true and R is not the correct explanation of A.
3. assertion is false but reason is true.
4. assertion is true but reason is false.

Assertion (A): A beam of white light gives a spectrum on passing through a hollow prism.

Reason (R): The speed of light outside the prism is same as the speed of light inside the prism.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true and R is not the correct explanation of A.
3. assertion is false but reason is true.
4. assertion is true but reason is false.