In a logic circuit, inputs A and B are connected to the anodes of two ideal p-n junction diodes D₁ and D₂ respectively. The cathodes of both diodes are joined together at a node X , which is grounded through a resistor R . The voltage signal at node X is fed to one input of a two-input NAND gate. A third input signal C is fed to the other input of the NAND gate. The final output of the NAND gate is Y . The logic leve

Step-by-step solution

The circuit consists of a diode-resistor logic gate followed by a NAND gate. For the diode-resistor circuit: when either input A or B is at logic 1 (high voltage), the corresponding diode is forward-biased, and the voltage at node X becomes high (logic 1 ). When both A and B are at logic 0 , both diodes are unbiased, and node X is pulled to ground (logic 0 ) through the resistor R . Thus, the logic at node X represents an OR gate: X = A + B . The signal X and input C are fed into a NAND gate. The final output Y is