Physics · Wave Optics

JEE Advanced 2024 — Paper 2 — Question 41

The maximum speed in μm/s\mu \mathrm{m} / \mathrm{s} at which the 8th 8^{\text {th }} bright fringe will move is

Question figure

Answer: 24

Numerical answer — enter this value.

Step-by-step solution

y=8×6000×10−10×1(0.8+0.04sin⁡ωt)×10−3y=\frac{8 \times 6000 \times 10^{-10} \times 1}{(0.8+0.04 \sin \omega t) \times 10^{-3}} y=48×10−4(0.8+0.04sin⁡ωt)y=\frac{48 \times 10^{-4}}{(0.8+0.04 \sin \omega t)}

∣dydt∣=+48×10−4(0.8+0.04sin⁡ωt)2(0.04ωcos⁡ωt)t=0,v=vmax⁡vmax⁡=48×10−4×0.04×0.08(0.8)2=24×10−6 m/s=24μ m/s\begin{aligned} & \left|\frac{d y}{d t}\right|=+\frac{48 \times 10^{-4}}{(0.8+0.04 \sin \omega t)^{2}}(0.04 \omega \cos \omega t) \\ & t=0, v=v_{\max } \\ & v_{\max }=\frac{48 \times 10^{-4} \times 0.04 \times 0.08}{(0.8)^{2}}=24 \times 10^{-6} \mathrm{~m} / \mathrm{s}=24 \mu \mathrm{~m} / \mathrm{s} \end{aligned}

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Exam
JEE Advanced 2024
Paper
Paper 2
Subject
Physics
Chapter
Wave Optics
Topic
Young's Double Slit Experiment and Its Modifications