Question

A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of $\lambda$ An alpha particle having certain kinetic energy has the same de-Brogle wavelength $\lambda$ The ratio of kinetic energy of proton and that of alpha particle is:

• A. $2: 1$
• B. $4: 1$
• C. $1: 4$
• D. $1: 2$

Answer 1

Answer: (B)

$4: 1$

Answer 2

The correct option is(B): 4:1

$KE=\frac{p^2}{2m}​=\frac{h^2}{2mλ^2}​$
$\frac{KE_p}{​​KE_α}​=\frac{​m_α}{m_p}​​=4:1$