यंग के द्वि-स्लिट प्रयोग (Young's double-slit experiment) में फ्रिज चौड़ाई 2 mm है। पर्दे पर केंद्र से एक ही ओर स्थित 13वें दीप्त फ्रिंज (bright fringe) और चौथे अदीप्त फ्रिंज (dark fringe) के बीच की दूरी होगी:

In Young's double slit experiment using monochromatic light of wavelength λ, the intensity of light at a point on the screen where the path difference is λ is K units. The intensity of light at a point where the path difference is λ3 will be:

Unpolarized light of intensity I0 = 40 W/m2 is incident on a polaroid. The transmitted light then passes through a second polaroid whose pass axis is inclined at 30° to the first. Find the intensity of light emerging from the second polaroid.