Physics - Wave Optics Question with Solution | TestHub

Intensity $\propto (\text{ amplitude }{)}^2$ $$\begin{array}{rl}& \frac{I_1}{I_2}=\frac{16}{9}=\frac{a_1^2}{a_2^2}\\ & \Rightarrow {\mathrm{a}}_1=4;{\mathrm{a}}_2=3\end{array}$$ Therefore the ratio of intensities of bright and dark parts $$\frac{I_{\text{Bright }}}{I_{\text{Dark }}}=\frac{{\left(a_1+a_2\right)}^2}{{\left(a_1-a_2\right)}^2}=\frac{(4+3{)}^2}{(4-3{)}^2}=\frac{49}{1}$$