If `lamda_0` stands for mid-wavelength in the visible region, the de Broglie wavelength for 100 V electrons is nearest to

Options

A. `(lamda_0)/(5)`
B. `(lamda_0)/(50)`
C. `(lamda_0)/(500)`
D. `(lamda_0)/(5000)`

Answer

D

Explanation

Order of magnitude calculation is enough.
`(2m_eeV)^((1)/(2))=(2xx9xx10^(-31)xx100xx1.6xx10^(-19))^((1)/(2))`
`approx5xx10^(-24)kgms^(-1)` and `haprrox6xx10^(-34)Js`
So, `lamdaapprox10^(-10)m`
Mid-wavelength in visible region is
`lamda_0approx5000xx10^(-10)m`
Thus, `lamda=(lamda_0)/(5000)`