IF an electron enters into a space between the plates of a parallel plate capacitor at an an angle `alpha` with the plates an leaves at an angle `beta` to the plates find the ratio of its kinetic energy while entering the capacitor of that while leaving.

Options

A. `((sinbeta)/(sinalpha))^(2)`
B. `((cos beta)/(cos alpha))^(2)`
C. `((cos alpha)/(cos beta))^(2)`
D. `((sin alpha)/(sin beta))^(2)`

Answer

B