Why do we observe the dark and bright colored frings in newton's ring?

Answer 1

the newton's rings are formed due to the phenomenon of thin film interference.

here, the condition for constructive interference(the ring appearing bright) is that the optical path difference between interfering waves should be an integral multiple of the wavelength.

the optical path difference is given by 2t-(l/2) if t is the thickness of the air film at that point and l is the wavelength of light.

at the central point, the lens touches the surface so thickness t=0. thus the optical path difference is simply l/2, which is the condition for destructive interference, not constuctive interference.

so the central spot has to always be dark.

Answer 2

from what i know.....at the centre the thickness of air is 0 ie ur path difference is 0.......which is possible only if there is a destructive interference as delta(x)=(n)(lamda) in newtons ring experiment

no as far as I know when the path difference is zero we have constructive interference because the crest fall on crest in this case

Answer 3

The dark and bright colored fringes in newton's ring are because of destructive and constructive interferences. The light fringes represent constructive interference while the dark fringes represent dark interference.

Answer 4

Why centre of newton ring is dark? Newton's rings are created by the destructive and constructive interference between the light...

Is the central fringe dark or bright? Because the path difference or the phase difference between two waves is zero

Why does the central region appear dark in newton rings? the newton's rings are formed due to the phenomenon of thin film interference. here, the...

Where have the fringes formed in newton's ring? the rings are formed in the air film in the space between the lens and the glass plate.

Answer 5

because of destructive interference ,destructive interference is when one crest i.e. high point and trough i.e. low point is there.

Answer 6

by using plano concave lens in place of plano convex lens