In a digital logic circuit, inputs A and B are connected to a NAND gate. The output of this NAND gate and the input B are then fed into an unknown logic gate G . The final output of the circuit is Y . The logic states of A , B , and Y are observed over four distinct time intervals as follows: Interval 1: A is Low, B is Low, Y is Low Interval 2: A is High, B is Low, Y is Low Interval 3: A is Low, B is High, Y is High

Step-by-step solution

Let the output of the NAND gate be X . The Boolean expression for X is X = A B . Let us evaluate X for each given interval: Interval 1: A = 0 , B = 0 X = 0 0 = 1 . The inputs to gate G are X = 1 , B = 0 , and the output is Y = 0 . Interval 2: A = 1 , B = 0 X = 1 0 = 1 . The inputs to gate G are X = 1 , B = 0 , and the output is Y = 0 . Interval 3: A = 0 , B = 1 X = 0 1 = 1 . The inputs to gate G are X = 1 , B = 1 , and the output is Y = 1 . Interval 4: A = 1 , B = 1 X = 1 1 = 0 . The inputs to gate G are X = 0 , B