Question

By properly combining two prisms made of different materials, it is possible to-

• A. Have dispersion without average deviation
• B. Have deviation without dispersion
• C. Have both dispersion and average deviation
• D. Have neither dispersion nor average deviation

Answer 1

Answer: (A), (B), (C)

Have both dispersion and average deviation

We know that, from the combination of two different material prisms, it can produce,

(i). Dispersion without average deviation
(ii). Deviation without dispersion
(iii). Both dispersion and average deviation.

But it is impossible to have neither dispersion nor average deviation from the combination of two different material prisms.

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(\text{A}\right),\left(\text{B}\right)$ and $\left(\text{C}\right)$ is the correct answer.

Why this question ? Key concept : It is impossible to have neither dispersion nor average deviation from the combination of two prisms made of different materials.