Red light of wavelength 633 nm from a helium-neon laser passes through a slit 0.380 mm wide. the diffraction pattern is observed on a screen 3.55 m away. define the width of a bright fringe as the distance between the minima on either side.

width of maximum intensity at the center of screen is 12 mm

Explanation:

Position of minimum intensity on the screen is given as

now we know that for first position of minimum intensity on the screen we have

now we know

now we have

now total angular width of central maximum is given as

now linear width is given as

snell's law

refractve index = sin incidence / sin refraction

the answer is the index of refraction of the second medium is higher. i just took the test.