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Why is it necessary for the light to fall normally on the glass plate?

Why is it necessary for the light to fall normally on the glass plate?

The light falls on glass plate is partially reflected and partially transmitted. The reflected light normally falls on the plano-convex lens placed on plane glass plate. This light reflected from upper and lower surface of the air film form between plane glass plate and plno-convex lens.

Why the glass plate used in the pathway of the light source should be inclined exactly at 45?

The angle between the incoming ray and the glass plate is 45 degree to make turns the light rays to 90 degrees and that’s why the rays fall normally on the plano-convex lens. Finally forms circular rings.

What happens if we use white light in Newton’s ring?

If white light is used in the Newton’s rings experiment, the colour observed in the reflected light is complementary to that observed in the transmitted light is complementary to that observed in the transmitted light through the same point.

Why do the rings get closer as the order of the Rings increase?

Rings get closer as the order increases (m increases) since the diameter does not increase in the same proportion. In transmitted light the ring system is exactly complementary to the reflected ring system so that the centre spot is bright.

What will happen if the lens is lifted slowly up the plate?

Answer. As the lens is lifted the difference in optical path between the two reflected rays will vary, thus slowly converting bright rings to dark and vice versa. This will be periodic change.

What will happen if few drops of liquid are introduced between the lens and glass?

What will happen if few drops of liquid is introduced between the lens and glass? A. The diameter of the rings will decrease because the diameter of the rings is inversely proportional to the refractive index.

What is the principle behind Newton’s rings formation?

Ans: 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 which is formed between the lens and glass sheet. A film of air which is of varying thickness is formed between the lens and the glass sheet.

How are newtons rings formed in a plano convex lens?

Newton rings are Alternate dark and bright rings formed due to the presence of air film when the plano-convex lens is placed on the glass plate is called newtons rings. The angle between the incoming ray and the glass plate is 45 degree to make turns the light rays to 90 degrees and that’s why the rays fall normally on the plano-convex lens.

When is a plano convex surface is placed on a glass plate?

When a plano-convex surface is placed on a glass plate, an air film of gradually increasing thickness is formed between the two and monochromatic light is allowed to fall normally on film and viewed in reflected light, alternate dark and bright rings are observed. These are known as Newton’s ring.

How does interference of light occur in Newton’s rings?

In case of Newton’s rings we have interference of light with thin air film formed between lower surface of convex lens and and plane surface. To get the visible interference effect the thickness of the film should be of the order of few wavelengths of the light used.

How are dark and bright rings formed in newtons ring experiment?

A.Alternate dark and bright rings formed due to presence of air film when plano convex lens is placed on glass plate is called newtons rings. Q.How are Newton’s rings formed?