An electron is moving through a field. It is moving `(i)` opposite an electric field `(ii)` perpendicular to a magnetic field as shown. For each situation the de - Broglie wave length of electron

Options

A. increasing , increasing
B. Increasing , decreasing
C. Decreasing , same
D. Same , same

Answer

C

Explanation

`lambda = (h)/(mv)`. Since `v` is increasing in case `(i)` , but it is not changing in case `(ii)`. Hence , in first case de - Broglie wavelength will change , but it second case , it remain the same