SatyamBhujan,
Apparently you have little circuit design experience, because the emitter follower is a very basic circuit.
The circuit has voltage gain of 1 (or very slightly less than 1). The current gain is limited to the inherent gain of the transistor. So the voltage on the lamp is approximately equal to the voltage at the base of the transistor (offset by the base emitter voltage drop, typically 0.6-0.7 V for silicon transistors). The circuit is non-inverting, meaning that an increase in the base voltage produces an increase in the output voltage. One advantage is that is it easy to use a grounded load.
The circuit with the load on the collector side can have voltage gain > 1. If the circuit has an emitter resistor, the voltage gain is set by the ratio of the collector and emitter resistances (as long as the ratio is less than the maximum the transistor can support). It is also possible to design circuits of this configuration where the DC operating point (bias currents) are somewhat independent of the gain. The laod is connected to the positive power supply, not ground. The output is inverted, meaning that an increase in the base voltage produces a decrease in the collector voltage.
You can look at any text on transistor circuit design for more information.
Lynn
