Question

In Young's double slit experiment, if one of the slits is covered with a thin transparent sheet, then:

• A. At maximum, intensity increases; At minimum, intensity increases
• B. At maximum, intensity decreases; At minimum, intensity decreases
• C. At maximum, intensity increases; At minimum, intensity decreases
• D. At maximum, intensity decreases; At minimum, intensity increases

Answer 1

The correct option is D At maximum, intensity decreases; At minimum, intensity increases

when one of the slits is covered with a thin transparent sheet the path travelled by the light through this slit increases. Thus a constructive interference no longer takes place at the previous maximum and thus the maximum intensity decreases. Similarly the destructive interference no longer takes place at the previous minimum and thus the minimum intensity increases.