Question

In dispersion without deviation :

• A. The emergent rays of all the colours are parallel to the incident ray
• B. Yellow coloured ray is parallel to the incident ray
• C. Only red coloured ray is parallel to the incident ray
• D. All the rays are parallel, but are not parallel to the incident ray

Answer 1

The correct option is B Yellow coloured ray is parallel to the incident ray

In case of dispersion without deviation, deviation is zero for only a particular colour, it is generally taken to be the colour lying in the middle of the spectrum i.e. yellow colour.

Therefore, option $\left(b\right)$ is the correct answer.