The de Borglie wavelength of a proton(charge = `1.6 xx 10^(-19)`C, mass = `1.6 xx 10^(-27)` kg) accelerated through a potential difference of 1 kV is

Options

A. 600 `dot(A)`
B. `0.9 xx 10^(-12)` m
C. 7 `dot (A)`
D. `0.9 dot A`

Answer

B

Explanation

`lambda = (h)/(p) = (h)/(sqrt(2mE)) = (h)/(sqrt(2mqV))`
`therefore lambda = (6.6 xx 10^(-34))/sqrt(2xx(1.6 xx^(-27))xx(1.6 xx 10^(-19))xx1000)`
or ` lambda = (6.6 xx10^(-34) xx 10^(22))/(1.6 sqrt 20) = 0.9 xx 10^(-12) m`