Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET 2016
Exam
NEET
Year
2016
Subject
Physics
Chapter
Wave Optics

NEET 2016 · Physics · Wave Optics

The intensity at the maximum in a Young's double slit experiment is...

The intensity at the maximum in a Young's double slit experiment is I0{I}_{0}. Distance between two slits is d=5λd = 5\lambda, where λ\lambda is the wavelength of light used in the experiment. What will be the intensity in front of one of the slits on the screen placed at a distance D=10dD = 10d?

Options

  1. AI0{I}_{0}
  2. BI04\dfrac{{I}_{0}}{4}
  3. C34I0\dfrac{3}{4}{I}_{0}
  4. DI02\dfrac{{I}_{0}}{2}

Correct answer

D. I02\dfrac{{I}_{0}}{2}

Step-by-step solution

In YDSE {I}_\max = {I}_{0}

Path difference at a point in front of one of shifts is

∆x=d(yD)=d(d2D)=d22D∆ x = d\left(\dfrac{y}{D}\right) = d\left(\dfrac{\dfrac{d}{2}}{D}\right) = \dfrac{{d}^{2}}{2D} (Herey=d2)( Herey = \dfrac{d}{2} )

∆x=d22(10d)=d20=5λ20=λ4∆ x = \dfrac{{d}^{2}}{2\left(10d\right)} = \dfrac{d}{20} = \dfrac{5\lambda}{20} = \dfrac{\lambda}{4}

Path difference is

ϕ=2πλ\Deltax=2πλ(λ4)ϕ = \dfrac{2\pi}{\lambda}\Deltax = \dfrac{2\pi}{\lambda}\left(\dfrac{\lambda}{4}\right)

ϕ=π2ϕ = \dfrac{\pi}{2}

So intensity at that point is

I = {I}_\max\cos^{2}\left(\dfrac{\theta}{2}\right)

I=I0cos⁡2(π4)=I02I = {I}_{0}\cos^{2}\left(\dfrac{\pi}{4}\right) = \dfrac{{I}_{0}}{2}
Practice Wave Optics on Quantrex Academy →

More from Wave Optics

An unpolarized light beam of intensity I_0 passes through a series of n Polaroids P_1… MHT CET Medical 2026In a single-slit Fraunhofer diffraction experiment, the first secondary minimum is… MHT CET Medical 2026In the Young's double slit experiment, the intensity of light at a point on the screen is… MHT CET Medical 2026Two images are considered "just resolved" according to Rayleigh's criterion when MHT CET Medical 2026In Young's double slit experiment, the slits are 2\ mm apart and are illuminated by… MHT CET Medical 2026In Young's double slit, 18 fringes are observed to be formed in a certain segment of the… MHT CET Medical 2026When the un-polarised light beam is incident from air to glass (n = 1.5) at the… MHT CET Medical 2026In Young's double-slit experiment, the intensity at a point is ((1)/(4)) of the maximum… MHT CET Medical 2026 Full Wave Optics list All NEET PYQs