A plane light wave with wavelength `lambda` and intensity `I_(0)` falls normally on a large glass
Channel: Doubtnut
Date: 16/08/2020

A plane light wave with wavelength `lambda` and intensity `I_(0)` falls normally on a large glass plate whose opposite side serves as an opaque screen with a round aperture equal to the first Fresnel zone for the observation point `P`. In the middle of the aperture there is a round recess equal to half the Fresnel zone. What must the depth `h` of that recess be for the intensity of light at the point `P` to be the highest? What is this intensity equal to?