Search any question & find its solution
Question:
Answered & Verified by Expert
If the slit width is $2 \mathrm{~mm}$ and wavelength of light used is $4000 Å$, then Fresnel distance is nearly
Options:
Solution:
1613 Upvotes
Verified Answer
The correct answer is:
$10 \mathrm{~m}$
(b) Slit width $\mathrm{a}=2 \mathrm{~mm}=2 \times 10^{-3} \mathrm{~m}$. $\lambda=4000 \mathrm{~A}^{\circ}=4 \times 10^{-7} \mathrm{~m}$.
Fresnel distance: $\mathrm{Z}_{\mathrm{F}}=\frac{\mathrm{a}^2}{\lambda}=\frac{4 \times 10^{-6}}{4 \times 10^{-7}}=10$
$$
\mathrm{Z}_{\mathrm{F}}=10 \mathrm{~m}
$$
Fresnel distance: $\mathrm{Z}_{\mathrm{F}}=\frac{\mathrm{a}^2}{\lambda}=\frac{4 \times 10^{-6}}{4 \times 10^{-7}}=10$
$$
\mathrm{Z}_{\mathrm{F}}=10 \mathrm{~m}
$$
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.