SOLUTION

NOR gate

The NOR gate has two or more input signals but only one output signal. All inputs must be low and get a high output. In other words, the NOR gate recognizes only the input words whose bits are all 0S.

NOR means NOT OR, i.e. the OR output is NOTed. So, a NOR gate is a combination of an OR gate and a NOT gate.
Fig shows the logical structure of the NOR gate which is an OR gate followed by a NOT gate. Therefore, the final output is NOT the OR of the inputs. A small invert bubble has been added to the OR symbol to form the NOR symbol.