Question

The given circuit works as:

• A. NOR gate
• B. OR gate
• C. AND gate
• D. NAND gate

Hint:

This type of gate is sometimes called a "bubbled OR" gate, which by De Morgan's law is equivalent to a NAND gate \( (A' + B') \neq (A'+B')' \). The circuit shown is NOT a bubbled OR, but rather NOT gates feeding a NOR gate. The expression \(Y = (A' + B')' = A \cdot B\) shows that two NOT gates followed by a NOR gate function as an AND gate. It is essential to carefully apply Boolean algebra rules.

Answer 1

The Correct Option is C

To determine the function of the given circuit, let's analyze each part step by step.

1. The circuit contains two inputs, A and B.
2. Each input goes to an OR gate, which is indicated by the shape and logical function of the symbol.
3. The outputs of these OR gates are fed into another OR gate, whose output is then inverted by a NOT gate.
4. This configuration resembles a known logic gate combination.

Let's consider the logic:

1. The first OR gate: X = A + B
2. The output of this OR gate is passed through a NOT gate: \overline{X}
3. The logical expression for the circuit can be simplified as follows:

• The final output of the circuit is Y = \overline{X}, which can be simplified as Y = AB.

The logic function of the circuit corresponds to an AND gate as AB is the logical expression for an AND gate.

Therefore, the given circuit works as an AND gate.