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.

Solution:

The gate is the NAND gate .

BUT SIR CAN U PLEASE TELL ME HOW THIS ANSWER CAME.....

IAM NOT ABLE TO UNDERSTAND THE MERITNATION NOTES BEHIND LOGIC GATES.......

HOW TO WORK OUT SUCH TYPE OF QUESTIONS?????

Hi Sanal!

Refer the waveforms A, B and Y. The raised portion represents 1 (high) and lowered portion of the wave represents 0 (low).

During the interval between 0 and 1 (interval is marked at the bottom of the vertical dashed lines), both A and B are 1. The output of NAND gate for this input is 0. During the interval between 1 and 2, A and B are 0 (low). So, the output is 1. Similarly you can check the rest of the signal for intervals between 2 to 3, 3to 4 and so on.

Hope this is clear to you.