Question icon
Grade 8General Physics

the output of a two NAND gate is fed as input to an OR gate. write the truth table for the final output of combination. Name this new logic gate.

Profile image of prasanjeet kumar
12 Years agoGrade 8
Answers icon

1 Answer

Profile image of Askiitians Tutor Team
ApprovedApproved Tutor Answer1 Year ago

To analyze the scenario you've presented, we need to break down the operation of the two NAND gates and how their outputs interact with the OR gate. This combination of gates creates a new logic function, which we can explore through a truth table.

Understanding NAND and OR Gates

A NAND gate outputs a low signal (0) only when all its inputs are high (1). In all other cases, it outputs a high signal (1). An OR gate, on the other hand, outputs a high signal (1) if at least one of its inputs is high (1).

Truth Table Construction

Let’s denote the inputs to the two NAND gates as A and B. The outputs of the two NAND gates will be labeled as X and Y. The final output from the OR gate will be labeled as Z. Here’s how we can construct the truth table step by step:

  • First, calculate the outputs of the two NAND gates (X and Y).
  • Then, use these outputs as inputs to the OR gate to find the final output (Z).

Truth Table

A B X (A NAND B) Y (A NAND B) Z (X OR Y)
0 0 1 1 1
0 1 1 1 1
1 0 1 1 1
1 1 0 0 0

Analyzing the Results

From the truth table, we can see that the final output Z is high (1) for all combinations of inputs A and B, except when both are high (1). This means that the output Z is low (0) only when both inputs are high, which is characteristic of a NOR gate.

Identifying the New Logic Gate

Thus, the combination of two NAND gates followed by an OR gate effectively behaves like a NOR gate. This is a fascinating example of how different logic gates can be combined to create new logical functions.

In summary, the final output of this combination of gates is a NOR gate, which is defined by the truth table we constructed. This illustrates the versatility of logic gates in digital circuits and how they can be used to achieve various logical operations.