White light (wavelengths ranging from 400 nm to 750 nm) shines through two slits and an interference pattern is displayed on a screen 1.5 m away.
Q. How wide is the first order spectrum on the screen (that is, how far away is the first order bright fringe from the 400 nm light and the first order bright fringe from the 750 nm light)?
(a) 17 cm
(b) 23 cm
(c) 38 cm
(d) 45 cm
(e) 51 cm