Download App

Wave Optics — Physics STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 SciencePhysicsWave Optics3 Marks
Question
In Young's double$-$slit experiment, the distance between two consecutive bright fringes on a screen placed at $1.5 m$ from the two slits is $0.6\ mm$. What would be the fringe width, if the screen is brought towards the slits by $50\ cm$, keeping rest of the setting the same?
✓

Answer

Let $\lambda$ be the wavelengths of light used and $d$ the distance between the two sources $($i.e., slits$)$,
if $D$ is the distance between the sources and the screen, the fringe width is
$w =\frac{\lambda D}{d}$
For the same $\lambda$ and $d, W \propto D$.
$\therefore \frac{W_2}{W_1}=\frac{D_2}{D_1}$
Data: $W_1=0.6\ mm =6 \times 10^{-4} m ,$
$D_1=1.5 m , D_2=1 m$
$\therefore W_2=\frac{W_1 D_2}{D_1}$
$=\frac{6 \times 10^{-4} \times 1}{1.5}$
$= 4 \times 1 0 ^{- 4 }m~$
This is the required fringe width.

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 "Answer the following in Brief" from Wave Optics→Wave Optics — all question types→Physics STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

Derive an expression for the radius of the $n^{th}$ Bohr orbit for the hydrogen atom.
→
What are the steps through which a refrigerant goes in one complete cycle of refrigeration?
→
Define the SI unit of magnetic induction from Lorentz force.
→
Obtain an expression for the torque acting on a rotating body with constant angular acceleration. Hence state the dimensions and SI unit of torque.
→
The photoelectric work function for a metal is \(4.2 eV\). If the stopping potential is \(3 V\), find the threshold wavelength and maximum kinetic energy of emitted electrons. (Velocity of light in air \(=3 \times 10^8 m / s\),) Planck's constant \(=6.63 \times 10^{-34} J - s\), Charge on electron \(=1.6 \times 10^{-19} C\) )
→
Calculate the average molecular kinetie energy: (a) per kilomole (b) per kilogram of oxygen at $27^{\circ} C$.(R=8320 $J / kmole K$, Avogadros number $=6.03 \times 10^{26}$ molecules $/ K$ mole)
→
From the definition of linear SHM, derive an expression for the angular frequency of a body performing linear SHM.
→
Derive an expression for terminal velocity of a spherical object falling under gravity through a viscous medium
→
Derive an expression for the net torque on a rectangular current carrying loop placed in a uniform magnetic field with its rotational axis perpendicular to the field.
→
Two diametrically opposite points of a metal ring are connected to two terminals of the left gap of meter bridge. The resistance of \(11 \Omega\) is connected in right gap. If null point is obtained at a distance of \(45 cm\) from the left end, find the resistance of metal ring.
→