How would you set up a circuit to obtain NOT gate using a transistor?

Explanation

The NOT gate can be realised by making use of transistor . The base (B) of the transistor is connected to A through a resistor `R_(b)` while the emitter (E ) is earthed . The collector is earthed through a resistor RC and a 5V battery in following two case :
(a) A = (0) . The base of the transistor also gets earthed . Therefore , base - emitter junction in not forward biased . Since the base current in zero , the collector current is also zero. The transistor is said to be in cut - off mode . The output y will be equal to the voltage of battery connected to collector i.e., 5V. In other words , When A = 0 , y = 1 .

(b) A = 1 . The base- emitter junction gets forwards biased and it leads to a large collector current . The transistor is said to have gone to saturation . The voltage drop across the resistor `R_(c)` in just equal to 5 V and the output y is very nearly 0.