In a P-type silicon sample, the hole concentration is $$2.25\times10^{15}/cm^3$$. If the intrinsic carrier concentration is $$1.5\times10^{15}/cm^3$$ , the electron concentration is

The Early-Effect in a bipolar junction transistor is caused by

The Ebers-Moll model is applicable to

A BJT is said to be operating in the saturation region if