A potential barrier of 0.50 V exists across a p-n junction.
An electron with a speed of `5.0 xx 10^5 ` m/s approaches the p-n junction from the n-side. With what speed will it enter the p-side ?

Explanation

Suppose the electron has a speed `v_1 `, when it enters the depletion layer and `v_2`, when it comes out of it. As the potential energy increases by `e xx 0.50 `V, from the principle of conservation of energy.
` 1/2 m upsilon_(1)^(2) = e xx 0.50 + 1/2 m upsilon_(2)^(2)`
`1/2 ( 9.1 xx 10^(-31)) ( 5 xx 10^5 )^2 `
`= 1.6 xx 10^(-19) xx 0.5 +1/2 xx 9.1 xx 10^(-31) xx upsilon_(2)^(2)`
Solving this, ` upsilon _2 = 2.7 xx 10^5 m//s`