Table of Contents
Why the interference pattern is in circular shape?
The path difference between the reflected ray and incident ray depends upon the thickness of the air gap between lens and the base. As the lens is symmetric along its axis, the thickness is constant along the circumference of a ring of a given radius. Hence, Newton’s rings are circular.
What is an interference pattern formed by?
Any type of wave, whether it be a water wave or a sound wave should produce a two-point source interference pattern if the two sources periodically disturb the medium at the same frequency. Such a pattern is always characterized by a pattern of alternating nodal and antinodal lines.
Why does the interference form a light pattern and a dark pattern?
This double-slit interference pattern of alternating dark and bright bands or fringes comes about because light arriving at various positions has traveled different distances from the two slits to the screen. The distance from a to y is the same as the distance from c to y.
Why are circular fringes formed in Newton rings?
4.In a newtons ring set up the air film is enclosed below the convex lens. The thickness of the film is constant over a circle (or concentric circles) having center at the center of the lens. Hence the fringes are circular.
Can the central fringe of an interference pattern be a dark fringe?
The bright lines indicate constructive interference and the dark lines indicate destructive interference. The bright fringe in the middle of the diagram on the right is caused by constructive interference of the light from the two slits traveling the same distance to the screen.
Why the central spot is dark in Newton ring?
The central fringe in Newton’s rings is dark in the case of the reflected system because the air film thickness formed at the centre between the glass plate and the lens is zero. Hence, at the geometrical path difference between the incident and reflected rays from the glass plate is zero.
How Newton rings are formed?
The rings of Newton’s are formed as a result of interference which is between the light waves that are reflected from the top and bottom surfaces of the air film formed between the lens and glass sheet. When a ray is incident on the lens surface then it is reflected as well as refracted.
What does interference of light mean?
Interference is the phenomenon in which two waves superpose to form the resultant wave of the lower, higher or same amplitude. The most commonly seen interference is the optical interference or light interference. This means that light waves coming out of a source do not have a constant amplitude, frequency or phase.