A my of light in glass is incident at an angle of 30° on the surface separating glass from air. The ray is refracted in the air at an angle of and the refracted ray in the plane of the incident ray,

Correct option is B

When light passes from a denser medium (glass) to a rarer medium (air), it bends away from the normal due to the increase in speed. This follows Snell’s Law, which states:$$n_1\text{sin⁡i}=n_2\text{sin⁡r}$$​​

where:

• n1n_1n₁ = refractive index of glass (~1.5)
• n2n_2n₂ = refractive index of air (1.0)
• i=30∘i = 30^\circi=30^∘ (angle of incidence in glass)
• $r=?$ (angle of refraction in air)

Using Snell’s Law:

​$$1.5sin⁡30^∘=1.0sin⁡r\\ \ \\ 1.5\times0.5=1.0 sinr \\ \ \\ 0.75=sinr \\ \ \\ r=sin^{-1}(0.75)\approx48.6\degree$$​​

Since 48.6° is more than 30°, the refracted ray bends away from the normal. Additionally, according to the laws of refraction, the refracted ray always lies in the plane of the incident ray.