In a Young's double slit experiment, light from a laser source fa… - Vidyadip

MCQ

In a Young's double slit experiment, light from a laser source falls on a pair of very narrow slits separated by $1.0 \,\mu m$ and bright fringes separated by $1.0 \,mm$ are observed on a distant screen. If the frequency of the laser light is doubled, the separation of the bright fringes is .......$\,mm$ ?

A
$0.25$
✓
$0.5$
C
$1.0$
D
$2.0$

✓

Answer

Correct option: B.

$0.5$

b
(b)

In Young's double slit experiment, fringe width or fringe separation is

$\beta=\frac {\lambda D}{d}= \frac{cD}{fd}$

As, $\quad \lambda=c / f$

$\therefore \beta \propto \frac{1}{f}$, keeping other parameters constant.

So, when frequency $f$ is doubled, fringe separation $\beta$ is halved.

$\therefore \quad \beta=\frac{1}{2} \,mm =0.5 \,mm$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 10. Wave optics→10. Wave optics — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

In an electron gun the control grid is given a negative potential relative to cathode in order to

A big circular coil of $1000$ turns and average radius $10\,m$ is rotating about its horizontal diameter at $2\,rad.s ^{-1}$. If the vertical component of earth's magnetic field at that place is $2 \times 10^{-5}\,T$ and electrical resistance of the coil is $12.56 \,\Omega$, then the maximum induced current (in $A$) in the coil will be :

The speeds of microwaves, infrared waves, and ultraviolet waves are $V_m, V_i$, and $V_u$ respectively. Identify the correct combination showing the different waves in vacuum.

Calculate the wavelength of electromagnetic waves of frequency $300\ MHz.$

If focal length of the objective lens is increased, then

A bar magnet of magnetic moment $10^4\,J/T$ is free to rotate in a horizontal plane. The work done in rotating the magnet slowly from a direction parallel to a horizontal magnetic field of $4×10^{-5}\, T$ to a direction $ 60° $ from the field will be.....$ J$

The ratio of the equivalent resistance of the network (shown in figure) between the points $a$ and ${b}$ when switch is open and switch is closed is ${x}: 8 .$ The value of ${x}$ is ..... .

If an electron and a proton having same momenta enter perpendicular to a magnetic field, then

In a series $\text{LCR}$ circuit, the voltage across the resistance, capacitance and inductance is $10 V$ each. If the capacitance is short circuited the voltage across the inductance will be

$X-$ ray beam can be deflected by