The wavelength of electron waves in two orbits is `3:5`. The ratio of kinetic energy of electrons wil be

Options

A. `25:9`
B. `5:3`
C. `9:25`
D. `3:5`

Answer

a

Explanation

`(lambda_1)/(lambda_2)=3/5`
kinetic energy (KE)`-1/2mv^(2)`
`KE=1/2(h^(2))/(mlambda^(20))(therefore lambda=h/(mv),lambda^(2)=(h^(2))/(m^(2)v^(2))impliesmv^(2)=(h)/(mlambda^(2)))`
`(KE)_1/(KE)_2=lambda_2^(2)=((5)/(3))^(2)=25/9`
`therefore (KE)_1:(KE)_2=25:9`