Question

Draw a circuit diagram of n-p-n transistor amplifier in CE cofiguration. Under what condition does the transistor act as an amplifier ?

Answer 1

Condition : The transistor must be operated close to the centre of its active region.

Alternatively 

The base-emitter junction of the iransistor must be (suitable) forward biased and the collector emitter junction must be (suitably) reverse  biased