The output of NOR gate is connected to NOT gate. Let Y1 be the output of NOR gate and the final output of the combination of the two - gates be Y. The out put of NOR gate is 1 only when both the inputs are zero, while in NOT gate, the input gets inverted. Using these facts, the truth table for the given arrangement can be written as below:
It is the truth table of OR gate. Therefore, the given circuit acts as Or gate
The output of two NOT gates are connected to NOR gate Let Y1 and Y2 be the outputs of the two NOT gates and the final output of the combination of three gates be Y. In a NOT gate, the input gets inverted, while the out put of a NOR gate is 1 only when both the inputs are zero. Using these facts, the truth table for the given arrangement can be written as below:
It is the truth table of AND gate. Therefore, the given circuit acts as AND gate.
