KitsGuru Transistor as a NOR gate Educational Electronic Hobby Kit

The NOR gate is a digital logic gate that implements logical NOR. A HIGH output (1) results if both the inputs to the gate are LOW (0); if one or both input is HIGH (1), a LOW output (0) results. NOR is the result of the negation of the OR operator. It can also be seen as an AND gate with all the inputs inverted. If any one of the switch S2/S3 is closed, the transistor corresponding to that turns on and hence the output (v5) goes to low. The output becomes high only when both the switches are opened.