JEE Physics 2023 Question with Solution

Given: A circuit diagram with two inputs $A$ and $B$ and output $Y$.

Find: The logic gate represented by the circuit.

The circuit diagram represents a NAND gate. Let’s analyze the behavior of the circuit:

1. When both switches $A$ and $B$ are closed (ON state), the output is $0$ (the bulb does not glow) because the current flows directly to the ground.
2. In all other cases, the bulb glows, corresponding to an output of $1$.

This behavior matches the truth table of a NAND gate:

Thus, the circuit corresponds to the logic of a NAND gate, with the output given by:

Therefore, the correct option is B.

Given: The switch circuit output glows for most input combinations.

Find: Which logic gate matches the output pattern.

Check the output states directly:

• $A=0, B=0 \Rightarrow Y=1$
• $A=0, B=1 \Rightarrow Y=1$
• $A=1, B=0 \Rightarrow Y=1$
• $A=1, B=1 \Rightarrow Y=0$

A gate whose output is $0$ only when both inputs are $1$ is NAND.

Therefore, the correct option is B.