In a particular semiconductor device an oxide layers forms a barrier $0\mathrm{.}6$nm wide and $9\mathrm{.}00$ V high between two conducting wires. Electrons accelerates through $4\mathrm{.}00$V approach the barrier. a$)$ What fraction of the incident electrons will tunnel through the barrier? b$)$ Through what potential differenece should the elctrons be accelerated in order to increase the tunneling fraction by a factor of $2?$