To make sure a diode is correctly connected, you need to (1) identify its polarity and (2) confirm it behaves like a one‑way valve for current.

1. Identify anode and cathode

On a physical diode:

  • Look for a band or stripe on one end of the body – that end is the cathode (negative side).
  • The opposite side is the anode (positive side).
  • In circuit diagrams, the triangle side is the anode, and the bar line is the cathode. Current flows from triangle to bar (anode → cathode) in forward bias.

To connect it “correctly” for normal conduction, the anode must face the positive side of the circuit and the cathode toward the negative/load side (for example, in a simple rectifier: AC → diode (anode in, cathode out) → load → return).

2. Quick check with a multimeter

Most people confirm a diode connection using the multimeter’s diode‑test mode:

  1. Power off the circuit and discharge any capacitors for safety and to avoid false readings.
  1. Set the multimeter to Diode Test mode.
  1. Connect red probe to anode and black probe to cathode :
    • A good silicon diode shows a forward voltage drop of about 0.6–0.7 V.
  1. Reverse the probes (red to cathode , black to anode):
    • The meter should show OL or a very high resistance, meaning it is blocking current in reverse.

If you see this “conducts one way, blocks the other” behavior with the probes matching your intended polarity in the circuit , your diode is both healthy and oriented correctly.

3. Simple mental rule

  • Band (cathode) goes to the more negative side for forward conduction.
  • If your circuit symbol shows a bar, line that bar up with the band on the physical diode.

Follow those steps, and you can be confident your diode is connected the right way. Information gathered from public forums or data available on the internet and portrayed here.