Question.10
What will happen if the optocoupler is not used ?
Select Answer
The noise or voltage fluctuations in the relay circuit may also induce noise in Arduino’s circuit.
Voltage spikes or back EMF from the relay (when relay is switched off) could potentially feed back into the Arduino.
Incorrect Resistor value can draw a large amount of current into the Transistor's base, resulting in GPIO damage.
All of the above.
