1. When no object is detected:
o The OUT pin of the IR sensor is HIGH (close to 9V), so the voltage at the negative terminal of the buzzer and LEDs is equal to the voltage at their positive terminal.
o As a result, no current flows through the buzzer or the LEDs, and they remain OFF.
2. When an object is detected:
o The OUT pin of the IR sensor goes LOW (close to 0V or GND).
o This creates a potential difference across the buzzer and LEDs, allowing current to flow from the +ve terminal of the battery through the buzzer and LEDs to the OUT pin.
o Both the LEDs and buzzer will turn ON as long as the object is detected.