MCQ
In the visible region the dispersive powers and the mean angular deviations for crown and flint glass prisms are $\omega, \omega^{\prime}$ and $d, d$ respectively. The condition for getting deviation without dispersion when the two prisms are combined is
- A$\sqrt{\omega d}+\sqrt{\omega^{\prime} d^{\prime}}=0$
- B$\omega^{\prime} d+\omega d^{\prime}=0$
- ✓$\omega d+\omega^{\prime} d^{\prime}=0$
- D$(\omega d)^2+\left(\omega^{\prime} d^{\prime}\right)^2=0$
