Assertion Newton's rings are formed in the reflected system when the space between the lens and the glass plate is filled with a liquid of refractive index greater than that of glass, the central spot of the pattern is dark. Reason The refraction in Newton's ring cases will be from denser to rarer medium and the two interfering rays are reflected under similar conditions.

Question

Assertion Newton's rings are formed in the reflected system when the space between the lens and the glass plate is filled with a liquid of refractive index greater than that of glass, the central spot of the pattern is dark. Reason The refraction in Newton's ring cases will be from denser to rarer medium and the two interfering rays are reflected under similar conditions. (A) If both Assertion and Reason are true and the Reason is correct explanation of the Assertion (B) If both Assertion and Reason are true but Reason is not correct explanation of the Assertion (C) If Assertion is true but Reason is false (D) If Assertion is false but the Reason is true

Tardigrade Admin · Accepted Answer

When the medium between plane-convex lens and plane glass is rarer than the medium of lens and glass, the central spot of Newton's ring is dark. The darkness of central spot is due to the phase change of π which is introduced between the rays reflected from denser to rarer and rarer to denser medium.