Question

In a double-slit experiment, the second-order bright fringe is observed at an angle of 0.57

Answer 1

The relationship between the wavelenght of light, Lambda the slit separation, d and the angle of central axis, theta in Young's double-slit interference experiment is

d * sin (theta) = n * Lambda,,,

where n is orders of fringes = 0, 1, 2...

For this problem, Lambda = (* sin (theta)) * 1/n
= (0.0012 * sin(0.57)) * 0.5 in meters

Note: Check if the value given for theta in the above question is really in degrees or in radians and evaluate the final answer as appropriate