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 YDSE, the distance of the slits from the screen is increased by $25 \%$ and the separation between the slits is halved. If ' $\mathrm{W}$ ' represents the original fringe width, the new fringe width is
PhysicsWave OpticsMHT CETMHT CET 2021 (23 Sep Shift 2)
Options:
  • A $2 \mathrm{~W}$
  • B $2.5 \mathrm{~W}$
  • C 4W
  • D $1.5 \mathrm{~W}$
Solution:
2022 Upvotes Verified Answer
The correct answer is: $2.5 \mathrm{~W}$
$\begin{aligned} & \mathrm{E}=\frac{\lambda \mathrm{D}}{\mathrm{d}} \\ & \therefore \frac{\mathrm{W}_2}{\mathrm{~W}_1}=\frac{\mathrm{D}_2}{\mathrm{D}_1} \cdot \frac{\mathrm{d}_1}{\mathrm{~d}_2} \\ & \mathrm{D}_2=1.25 \mathrm{D}_1 \text { and } \mathrm{d}_2=\frac{\mathrm{d}_1}{2} \\ & \therefore \frac{\mathrm{W}_2}{\mathrm{~W}_1}=1.25 \times 2=2.5 \\ & \therefore \mathrm{W}_2=2.5 \mathrm{~W}\end{aligned}$

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.