Transistor as amplifier

This circuit may look like complicated at the first glance but if we take time to understand it it is very easy and intersting. I won't be going into physics behind this as it becomes much more complicated. The transistor can amplify only in active region means when Base-Emitter junction is forward biased and Base-coollector region is reverse biased and this can be achived by the biasing voltages VCC(V1) and VBB(V1) VBB>=VCC this condition has to be satisfied. Now if we apply any signal at the input side we get the amplified version but out of phase with input Using a single transistor we cannot generate a perfect amplified version of input but it takes a lot of transistors to do so Using opamps we can genarate the perfect amplified signal.