When a ray of light from air enters a denser medium, it:

1. bends away from the normal
2. bends towards the normal
3. goes undeviated
4. is reflected back

A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incidence is:

1. 0°
2. 45°
3. 60°
4. 90°

The diagram given below shows light travelling from air into glass. Four angles A, B, C and D are shown. Which of the following formulae is used to calculate the refractive index μ of the glass?

1. μ = $\dfrac{\text{sin A}}{\text{sin C}}$

2. μ = $\dfrac{\text{sin C}}{\text{sin A}}$

3. μ = $\dfrac{\text{sin B}}{\text{sin C}}$

4. μ = $\dfrac{\text{sin B}}{\text{sin A}}$

The incorrect statement among the following is:

1. When a ray of light gets refracted from a denser to a rarer medium, the speed of light decreases.
2. The frequency of light does not change on refraction.
3. The speed of light V in a medium is related to its wavelength λ and frequency f as V = fλ
4. The incident ray, the refracted ray and the normal at the point of incidence all lie in one plane.