Effect on newton''s ring, Physics

Q. What will be effect on Newton's rings if;

(i)      A little oil (µ = 1.65) is introduced between the lens (µ - 1.5) and the glass plate (µ = 1.75).

(ii)    A Plano-convex lens of small radius is used.

(iii)   A plane mirror is placed instead of the glass plate below the Plano-convex lens.

(iv)   The Plano-convex lens is raised by height ?h from the surface of plane glass plate.

(v)    Interference fringes are produced by monochromatic light falling normally on wedge shaped film of cello phase whose refractive index is 1.4. The angle of wedge is 40 seconds and distance between successive fringes is 1.25 mm. Calculate wavelength of the light used.                  [R.T.U. (II Sem.) 2008]

Sol.(a) (I) When a little oil (µ = 1.65) is introduced between the lens (µ = 1.5) and the glass plate (µ = 1.75) as shown in fig. then is this situation both the boundaries i.e. lens to oil and oil to glass plate both are rarer to denser type, so a phase change of π will occur at both the boundaries. In result dark and bright rings (fringes) will interchanged within the area of liquid.

(ii) As we know that diameter of bright and dark ring is directly proportional to the square root of the radius of curvature of the lens. Hence if we use a lens of small radius of curvature, the diameter of the rings will be small and rings will get closer, This will effect on the percentage error in the measurement of diameter.

(iii) If we use plane mirror instead of glass plate the rays transmitted by the air film and striking the mirror will get reflected and no part will be transmitted at all, due to superposition of reflected and transmitted light a general illumination will formed and no fringe will be found i.e. Newton's ring will disappear. Because the condition of maxima and minima for reflected and transmitted light are just opposite to each other.

Posted Date: 7/12/2012 7:21:34 AM | Location : United States







Related Discussions:- Effect on newton''s ring, Assignment Help, Ask Question on Effect on newton''s ring, Get Answer, Expert's Help, Effect on newton''s ring Discussions

Write discussion on Effect on newton''s ring
Your posts are moderated
Related Questions
Newton 2nd law of motion proof

Define Teacup Engine? The astronaut was calmly drinking tea at five o'clock galactic time, as was his wont, when he had an urgent situation outside the shuttle and he had to do

how to find center of mass of an object?

If the angle of incidence is 60 degrees,then what is the angle of deviation?

In the figure below the closed surfaces A and B appear as closed curves. Find the flux through closed surface B.

What do you understand by rectifier? Illustrate working of half wave and full wave rectifiers with diagrams. Show the expression for its efficiency? Define a transistor and illu

When white light is normally occurrence on a diffraction grating the first order maximum for which colour of light occurs at the greatest angle with respect to the straight ahead d

If there is a fire accident in an industry, what  a safety enginner  will do? Ans) Normal 0 false false false EN-IN X-NONE X-NONE

What type of waves are electromagnetic waves? Feedback: Electromagnetic waves are transverse waves that the oscillations of the electric and magnetic fields are at right

what do you mean by retardation plates?explain their functioning by taking an example of a quarter wave plate