Please view the attached files to see if problem is in the code or the circuit. It's supposed to be a normal switch type circuit, just passing through arduino.
The arduino files and circuit diagram on proteus are attached.

int switchPin = 8;
int ledPin = 9;
int ctr = 0;

void setup() {
  // put your setup code here, to run once:
  pinMode(switchPin,INPUT);
  pinMode(ledPin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:

  if(digitalRead(switchPin)==LOW)
    digitalWrite(ledPin,LOW);
   else
    digitalWrite(ledPin,HIGH);
}

Moderators note : used code tags

 

And this is related to Test Instruments like scopes, DMMs, signal generators etc how?

 

And this is related to Test Instruments like scopes, DMMs, signal generators etc how?

I don't know which topic to post this thread under. Please guide me for the same.

 

What happens when you tie the reset high!!

 

Your if..else syntax is not correct: https://www.arduino.cc/reference/en/language/structure/control-structure/else/

The 220 Ohm resistor is probably too high for blue led. You need something like 68 Ohm.

 

I don't know which topic to post this thread under. Please guide me for the same.

How about 'Digital Circuit Design'? Or 'Embedded Systems and Microcontrollers'? Or how about 'Programmer's Corner'?

Of if that's too obvious, how about 'General Electronics' (the space for everything that doesn't seem to fit somewhere else)?

All of them are literally a lot more relevant to your question than just dumping it in 'Test instruments', which has absolutely *nothing* to do with the question at hand.

Anyways, it appears the thread has already been moved. It just would be nice if people would use their brain a bit before posting. Seriously, reading and understanding the categories is not rocket science.