Which side of a diode is positive?

Which side of a diode is positive?

The positive side is called the anode, and the negative one is called the cathode. The diode circuit symbol, with the anode and cathode marked. Current through a diode can only flow from the anode to the cathode, which would explain why it's important for a diode to be connected in the correct direction.

Does it matter which side of the LED you put the resistor?

The resistor can be on either side of the LED, but it must be present. When two or more components are in series, the current will be the same through all of them, and so it doesn't matter which order they are in.

How do you determine the polarity of a diode?

Sometimes it's easiest to just use a multimeter to test for polarity. Turn the multimeter to the diode setting (usually indicated by a diode symbol), and touch each probe to one of the LED terminals. If the LED lights up, the positive probe is touching the anode, and the negative probe is touching the cathode.

How do you tell if diode is forward or reverse bias?

Forward-bias is when the anode (the pointy part of the symbol) is positive and the cathode (the bar) is negative. Reverse-bias is when the anode is negative and the cathode is positive.