Question

The following figure shows the input waveforms (A, B) and the output waveform (Y) of a gate. Identify the gate, write its truth table and draw its logic symbol.

Answer 1

The truth table for the gate can be obtained from the waveforms (from t = 1) as

A	B	`Y=bar(AB)`
0	0	1
0	1	1
1	0	1
1	1	0

Therefore, from the truth table, we can say that the gate is a NAND gate. The logic symbol for the NAND gate is