Electronic Devices

A potential barrier of 0.4 V exists across a p-n junction. An electron enters the junction from the n-side with a speed of 6.0 \(\times\) 10⁵ ms^\(-\)1. The speed with which electron enters the p side will be \({x \over 3} \times {10^5}\) ms^\(-\)1 the value of x is _____________.

(Given mass of electron = 9 \(\times\) 10^\(-\)31 kg, charge on electron = 1.6 \(\times\) 10^\(-\)19 C.)