An electron is moving with an initial velocity `vecv=v_(0)hati` and is in a magnetic field `vecB=B_(0)hatj`. Then it's de-Broglie wavelength

Options

A. remains constant
B. increases with time
C. decreases with time
D. increases and decreases periodically

Explanation

Given, `" "v=v_(o)hatiimpliesB=B_(0)hatJ`
Foece on moving lectron due to magnetic field is, `F=-e(vxxB)`
`" "=-e[v_(0)ixxB_(0)j]implies=-ev_(0)B_(0)K`
As this force is perpendicular to v and B, so the magnitude of v will not change , i.e., momentum (= mv) will remain constant in magnitude. Hence,
de-Broglie wevelength `lamda=(h)/(mv)` remaihns constant.