In a 10-μm long bar of donor-doped silicon, what donorconcentration is needed to realize a current density of 1 mA/μm2 in response to an appliedvoltage of 1V. (note : Although the carrier mobilities change withdoping concentration, as a first approximation you mayassume μn to be constant and use thevalue for intrinsic silicon, 1350 cm2 / V*s).