Question

In YDSE, the ratio of maximum and minimum intensities of fringe system is 4 : 1. The amplitudes of the coherent sources are in the ratio of –

• A. 1 : 1
• B. 3 : 1
• C. 1 : 4
• D. 5 : 1

Answer 1

Answer: (B)

3 : 1

Answer 2

$\frac{\mathbf{I}_{\mathbf{\max}}}{\mathbf{I}_{\mathbf{\min}}}$= $\frac{4}{1}$ = $\left\lbrack \frac{\sqrt{I_{1}} + \sqrt{I_{2}}}{\sqrt{I_{1}} - \sqrt{I_{2}}} \right\rbrack^{2}$

\ 2 = $\frac{\sqrt{I_{1}} + \sqrt{I_{2}}}{\sqrt{I_{1}} - \sqrt{I_{2}}}$

\ $\sqrt{\frac{I_{1}}{I_{2}}}$= 3 =$\frac{A_{1}}{A_{2}}$