An electron revolve round the nucleous with the radius of the circular orbit is 'r' . To double the kinetic energy of the electron its orbital radius will be

Options

A. `v//sqrt2`
B. `sqrt2 r`
C. `2 r`
D. `r //2`

Answer

B

Explanation

`KE_(2)=2KE_(1)`
`(1)/(2) mr_(2)^(2) omega ^(2)=2+(1)/(2) mr_(1)^(2) omega^(2)`
`r_(2)^(2)=2xxr_(1)^(2)`
`r_(2)=sqrt2 r `