Consider a ring of radius r due to thickness t of air film as shown in the. Sir isaac newton discovered bright and dark concentric rings when he held two lenses. To determine radius of curvature of a planoconvex lens using newtons ring. Pdf newtons rings is a phenomenon in which an interference pattern is created by the reflection of light between two surfacesa spherical surface and. Coherent light phase relationship path difference interference in thin film. To study the formation of newton s rings in the airfilm in between a planoconvex lens and a glass plate using nearly monochromatic light from a sodiumsource and hence to determine the radius of curvature of the planoconvex lens. In transmitted light the ring system is exactly complementary to the reflected ring system so that the centre spot is bright. To determine the wavelength of sodium light by newtons ring method. The purpose of this experiment is to test the consistency of the theoretical. The experimental setup used for the experiment is shown in fig. To observe newton rings formed by the interface of produced by a thin air film and determine the radius of curvature of a planoconvex lens. To see and adjust the just merged potion of the colors. In this experiment you will study the phenomenon of newtons rings, and use it to a measure the wavelength of light, and b the refractive index of water.
Newtons rings are nothing but concentric circular alternate bright and. Pdf in an earlier work shankar kumar jha, a vyas, o s k s sastri. Newtons rings is a phenomenon in which an interference pattern is created by the reflection of. Such fringes were first obtained by newton and are known as newton s rings. It is named after isaac newton, who investigated the effect in his 1704 treatise opticks. To determine the wavelength of sodium light using newtons.
As a result, we have the deviation of i from its theoretical value of 0. Young by his famous double slit experiment and has established the wave nature of light. Condition for formation of bright and dark fringes. Fizeau1 fringes like newtons rings, but the order is maximum for central disc unlike that in. When a parallel beam of monochromatic light is incident normally on a combination. The wavelength of monochromatic light can be determined as. Py2107 newtons rings physics 2107 newtons rings experiment 5.
In this optics experiment, a convex lens is placed on a reflecting surface. We could directly combine the above equations and solve for r. To determine the wavelength of sodium light by newtons ring. If two phaselocked wave trains of the same frequency and plane of polarisation coherent light overlap, after travelling different paths, interference occurs.
186 759 615 1583 1287 528 49 316 1425 92 1076 28 450 344 1144 599 406 1138 1206 1413 773 5 1160 997 653 804 982 1597 1279 326 1142 194 885 313 1234 1092 178