A logic circuit consists of two logic gates, G₁ and G₂ . The inputs A and B are fed into gate G₁ . The output of G₁ is then connected simultaneously to both the inputs of gate G₂ . If the final output of the circuit is equivalent to an OR gate, which of the following correctly identifies gates G₁ and G₂ ?

Step-by-step solution

Let the output of gate G₁ be Y' . Since the output Y' is fed into both inputs of gate G₂ , G₂ acts as a single-input gate. If G₂ is a universal gate (NAND or NOR), it functions as a NOT gate, giving final output Y = Y' . We are given that the final output Y is equivalent to an OR gate, so Y = A + B . Therefore, Y' = A + B Y' = A + B . This means G₁ must produce the operation A + B , which is a NOR gate. Checking the options, if G₁ is a NOR gate and G₂ is a NAND gate (acting as a NOT gate), the final output is A + B