The fringe width for red colour as compared to that for violet colour is approximately

Step-by-step solution

We know that, fringe width, = D d where, D= distance between the screen and source, d= distance between the slits and = wavelength of light used. As we know that, aligned _ red & 2 _ violet _ red _ violet & = _ red _ violet = 2 _ violet _ violet =2 _ red & =2 _ violet aligned