In a Young's double slit experiment the intensity of light when slit is at distance λ from central is I. What will be the intensity at the distance of slit is (λ)/(6) ?

Correct answer: C. (3)/(4) I As, φ=(2 π)/(λ) Δ x φ=(2 π)/(λ) λ φ=2 π I=I_1+I_2+2 I_1 I_2 φ =I^ +I^ +2 I^ 2 π I=2 I^ +2 I^ =4 I^ When Δ x=(λ)/(6) , then φ=(2 π)/(λ) × (λ)/(6)=(2 π)/(6) I_1=I^ +I^ +2 I^ I^ (2 π)/(6) I_1=2 I^ +2 I^ (1 / 2) I_1=3 I^ (I_1)/(I)= 3 I^ 4 I^ =(3)/(4) or I_1=(3)/(4) I

AIIMS 2014

Exam: AIIMS
Year: 2014
Subject: Physics
Chapter: Wave Optics

AIIMS 2014 · Physics · Wave Optics

In a Young's double slit experiment the intensity of light when...

In a Young's double slit experiment the intensity of light when slit is at distance

\lambda

from central is I. What will be the intensity at the distance of slit is

\frac{\lambda}{6}

Options

A $\frac{I}{6}$
B $\frac{I}{12}$
C $\frac{3}{4} I$
D $\frac{I}{8}$

Correct answer

C. $\frac{3}{4} I$

Step-by-step solution

As,

\phi=\frac{2 \pi}{\lambda} \Delta x \Rightarrow \phi=\frac{2 \pi}{\lambda} \lambda

\phi=2 \pi

\therefore I=I_1+I_2+2 \sqrt{I_1 I_2} \cos \phi

=I^{\prime}+I^{\prime}+2 I^{\prime} \cos 2 \pi

I=2 I^{\prime}+2 I^{\prime}=4 I^{\prime}

When

\Delta x=\frac{\lambda}{6}

, then

\phi=\frac{2 \pi}{\lambda} \times \frac{\lambda}{6}=\frac{2 \pi}{6}

\therefore \quad I_1=I^{\prime}+I^{\prime}+2 \sqrt{I^{\prime} I^{\prime}} \cos \frac{2 \pi}{6}

I_1=2 I^{\prime}+2 I^{\prime}(1 / 2)

I_1=3 I^{\prime}

\therefore \quad \frac{I_1}{I}=\frac{3 I^{\prime}}{4 I^{\prime}}=\frac{3}{4}

\quad I_1=\frac{3}{4} I

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 2026 In a single-slit Fraunhofer diffraction experiment, the first secondary minimum is… MHT CET Medical 2026 In the Young's double slit experiment, the intensity of light at a point on the screen is… MHT CET Medical 2026 Two images are considered "just resolved" according to Rayleigh's criterion when MHT CET Medical 2026 In Young's double slit experiment, the slits are 2\ mm apart and are illuminated by… MHT CET Medical 2026 In Young's double slit, 18 fringes are observed to be formed in a certain segment of the… MHT CET Medical 2026 When the un-polarised light beam is incident from air to glass (n = 1.5) at the… MHT CET Medical 2026 In 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