Statement I: A transistor amplifier in common emitter configuration has a low input impedance.Statement II: The base to emitter region is forward biased.

In transistor, the emitter-base junction is forward bias while the base-collector junction is given a large reverse bias. Under forward bias the charge carriers move towards base causing the flow of current. The following figure shows the circuit of a common-emitter amplifier circuit using an n-p-n  transistor. The input (base-emitter) circuit is forward biased by a low voltage battery  VBE,  so that the resistance of the input circuit is small.The output (collector-emitter) circuit is reverse biased by means of a high voltage battery so that resistance of output is high. The weak input AC signal is applied across the base-emitter circuit and the amplified output signal is obtained across the collector--emitter circuit. Input impedance of common-emitter configuration =∆VBE∆IBVCE=ConstantHere, ∆VBE= voltage across base and emitter  ∆IB= base current of the order of few micro ampere.