Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
In a Young's double slit experiment, if the wavelength of light is increased by $50 \%$ and the distance between the slits is doubled then the percentage change in fringe width is
PhysicsWave OpticsAP EAMCETAP EAMCET 2023 (15 May Shift 2)
Options:
  • A $75$
  • B $50$
  • C $25$
  • D $15$
Solution:
2270 Upvotes Verified Answer
The correct answer is: $75$
Wavelength of light, $\lambda^{\prime}=50 \lambda$
Distance between the slit, $\mathrm{d}^{\prime}=2 \mathrm{~d}$ fringe width, $\beta^{\prime}=\frac{D \lambda^{\prime}}{d^{\prime}}$
$\begin{aligned}
& =\frac{D \times 0.50 \lambda}{2 d}=0.25 \beta \\
& \left|\frac{\beta^{\prime}-\beta}{\beta}\right| \times 100 \%=|0.25-1| \times 100 \% \\
& =75 \% .
\end{aligned}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.