Red light of wavelength `6500 Å` from a distant source falls on a slit `0.50 mm` wide. Calculate the distance between first two dark bands on each side of central bright band in the diffraction pattern observed on a screen placed `1.8 m` from the slit.

Answer

`4.68 mm`

Explanation

Distance between the first dark band on either side of central bright band = width of central maximum `= (2 lambda D)/(a)`