Optics Question 54
Question: Assertion : In Young’s double slit experiment, the fringes become indistinct if one of the slits is covered with cellophane paper. Reason : The cellophane paper decrease 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.
E) If assertion is false but reason is true.
Show Answer
Answer:
Correct Answer: C
Solution:
When one of 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 beam have different intensities or amplitudes.
Hence intensity at minima will not be zero and fringes will become indistinct.
