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Physics · 2025 · 2 marks
CBSE 2025 · Region 7 · Set 2 · Q19
The ratio of the intensities at maxima to minima in Young's double-slit experiment is 25: 9. Calculate the ratio of intensities of the interfering…
The ratio of the intensities at maxima to minima in Young's double-slit experiment is $\displaystyle 25: 9$. Calculate the ratio of intensities of the interfering waves.
Marking-scheme solution
\[\text { Calculating the ratio of intensities } 2
\] Given, \(\displaystyle \frac{\mathrm{I}_{\text {max }}}{\mathrm{I}_{\text {min }}}=\frac{25}{9}\)
\[\frac{\mathrm{I}_{\max }}{\mathrm{I}_{\min }}=\frac{\left(a_{1}+a_{2}\right)^{2}}{\left(a_{1}-a_{2}\right)^{2}}=\frac{25}{9}
\]
\[3\left(a_{1}+a_{2}\right)=5\left(a_{1}-a_{2}\right)
\]
\[\frac{a_{1}}{a_{2}}=\frac{4}{1}
\]
\[\frac{\mathrm{I}_{1}}{\mathrm{I}_{1}}=\frac{16}{1}
\]
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