the negative leg is shorter than the positive leg.
On an LED, one leg will be shorter than the other. The shorter leg is the negative polarity.
The side of any diode that must be negative in order for the diode to conduct is the "cathode".
Current flows from the anode (positive terminal) to the cathode (negative terminal) in a LED. The longer leg of the LED indicates the positive anode side, while the shorter leg represents the negative cathode side.
Current will only flow one way through an LED, so it has a positive leg and a negative leg. One of them is longer to signify which is which (longer is negative). The negative side also has a chamfered edge on the LED itself.
Cathode (negative) is the shortest leg and there is a flat edge on the base of the LED, and it must be connected to the negative wire or "-" connection. Anode (positive) is the longest leg, and must be connected to the positive wire or "+" connection, as electricity will only pass through a LED from positive to negative.
The long leg of the LED is the Anode. Connecting the Anode to the negative end of the dry cell would bias the LED off. It would not illuminate. It may also destroy LED.
Anode and cathode. Anode = negative lead, cathode = positive lead.
The longer leg of an LED is typically the positive (+) terminal, while the shorter leg is the negative (-) terminal. Additionally, the positive leg usually has a flat edge or a notch near it as a visual indicator.
The longest leg is the positive leg of any LED.
The length of the legs. The positive leg is always longer than the negative one.
The shorter leg on an LED is the cathode, which is usually indicated by a flat edge on the LED's plastic casing or a shorter leg compared to the anode.