Question: 13: Identify the equivalent logic gate represented by the given circuit :
(1) OR
(2) NOR
(3) AND
(4) NAND
Answer: Option (1)
Explanation:
In the given circuit, an LED is connected to a +6 V supply through a resistor. The LED glows when there is a conducting path to ground.
There are two switches connected in parallel between the LED and ground. Each switch can be either open (0) or closed (1).
If any one of the switches is closed, a complete path is formed from the supply to ground, allowing current to flow through the LED. Hence, the LED glows and the output is 1.
If both switches are open, there is no conducting path to ground. No current flows through the LED, so it does not glow and the output is 0.
Thus, the output is 1 when input A = 1 or input B = 1, and the output is 0 only when both inputs are 0.
This behavior exactly matches the truth table of an OR gate.
Therefore, the equivalent logic gate represented by the circuit is OR gate.