In hydrogen atom electron makes transist from n = 3 orbit to n = 2 orbit in time `1.2xx10^(-8)` s. Then calculate the average torque (in Nm) that acts during this transition.

Options

A. `1.055xx10^(-26)`
B. `4.40xx10^(-27)`
C. `1.7xx10^(-26)`
D. `8.79xx10^(-27)`

Answer

D

Explanation

`tau=(DeltaL)/(Deltat)=(L_(2)-L_(1))/(Deltat)`
`=((n_(2)h)/(2pi)-(n_(1)h)/(2pi))/(Deltat)=((n_(2)-n_(1))h)/(2piDeltat)`
`=((3-2)xx6.625xx10^(-34))/(2xx3.14xx1.2xx10^(-8))`
`=8.79xx10^(-27)`