fresnel biprism
TRANSCRIPT
*optical bench
* biprism
*Convex lens
*Sodium vapour lamp
*Slit
*Micrometer eyepiece
λ = βd
D
where,
λ – wavelength of light,
β – fringe width,
d- the distance between two virtual sources formed by biprism,
D- the distance between the slit and the eyepiece.
Slit ( source)
Biprism ( two virtual souse)
Stand for lens
Optical bench
Whole setup foe deterring the wavelength of sodium ligh by Fresnel's biprism
Whole setup for determining the diameter of wire by using difrraction in shadow region phenomenon:-
source
slit
Stand for wire
Screen or eyepiece
Screw to setup the slit axis ( i.e. parallel to wire)
Slit opening
Screw to adjust the width of the slit
Screw to adjust the height of the slit
SLIT:-
Screw to adjust the axis of Biprism
Screw to inset the Biprism properly
Biprism
Screw to adjust the height of the biprism
Tangent screw (to remove the lateral shift of the fringe pattern).
Biprismstand:-
Screw to adjust the axis of the wire
Wire to measure the diameter
Screw to fit the wire stand
Optical bench
Tangent screw.
Wire Stand:-
Micrometer reading
Screw to rotate the micrometer
Ramsden’s eyepiece( screen to see the fringes)
Main scale reading
Screw to adjust the upright position of screen.
Screen:-
To remove the bench error:-
slit Measuring rod
stand
How to remove the bench error:-
first of all measure the length of rod by optical bench and by scale both.
scale measure the actual length and optical bench measure the apparent one.
then find the error.
Precautions:-
Always first remove the lateral shift then onwards perform the experiment.