Statement-1 : In Young’s double slit experiment, the fringes become indistinct if one of the slits is covered with cellophane paper. Statement-2 : The cellophane paper decreases the wavelength of light.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion
B. If both assertion and reason are true but reason is not the correct explanation of the assertion
C. If assertion is true but reason is false.
D. If the assertion and reason both are false

Answer

C

Explanation

When one of the slits is covered with cellophane paper, the intensity of light emerging from the slit is decreased (because this medium is translucent). Now the two interfering beams have different intensities or amplitudes. Hence intensity at minima will not be zero and fringes will become indistinct.