Question

The ratio of the de Broglie wavelength of a proton and alpha particles will be `1:2` if their
A. velocity are in the ratio `1:8`
B. velocity are in the ratio `8:1`
C. kinetic energy are in the ratio `1:64`
D. kinetic energy are in the ratio `1:256`

Answer 1

Correct Answer - B
`lambda=v`
then `lambda=h/(mV)` or `lambda^(2)=h/m` So, `lambda=sqrt(h/m)`