In a Young's double slit experiment, the slits are separated by 0.3 ~mm and the screen is placed 1.5 ~m away. If the measured fringe width is 2 ~mm , the wavelength of the light used is

Step-by-step solution

Fringe width is given by = D d Rearranging for wavelength : = d D Substitute the given values: = 2 ~mm = 2 10⁻³ ~m d = 0.3 ~mm = 0.3 10⁻³ ~m D = 1.5 ~m = 2 10⁻³ 0.3 10⁻³ 1.5 = 0.6 10⁻⁶ 1.5 = 0.4 10⁻⁶ ~m Converting to nanometers: = 400 10⁻⁹ ~m = 400 ~nm Answer: 400 ~nm