Light of wavelength λ is incident on a slit. The first minima of the diffraction pattern is found to lie at a distance of 6 mm from the central maximum on a screen placed at a distance of 2 m from the slit. If the slit width is 0.2 mm, then the wavelength of the light used will be:

Explanation

To find the wavelength of the light, we can use the formula for the first minima of the diffraction pattern: d*sin(theta) = m*lambda, where d is the slit width, theta is the angle of diffraction for the first minima, m is the order of the minima (in this case m=1), and lambda is the wavelength of the light. Given that the first minima is at a distance of 6 mm from the central maximum and the screen is placed at a distance of 2 m from the slit, we can calculate the angle of diffraction. Substituting the values, we find that the wavelength of the light used is 6000 Å. Therefore, Option B is the correct answer. The other options are incorrect because they do not reflect the correct calculation based on the given parameters.