Choose the incorrect statements.

Options

A. An electron beam is used to obtain interference in a simple Young's double-slit experiment . If speed of electron is increased the fringe width decreases.
B. de-Broglie wavelength of electron is inversely proportional to the speed of electrons.
C. Two coherent point sources of light having non-zero phase difference are separated by a small distance. On the perpendicular bisector of line segment joining both the point sources, no constructive interference can be obtained
D. For two waves from coherent point sources to interference constructively at a point the magnitude of their phase difference at that point must be `2npi` (where n is non-negative integer)

Answer

C

Explanation

`lamda=(h)/(mv)`