Which characteristic is crucial for selecting a suitable resistor for a LED circuit?

A crucial characteristic for selecting a suitable resistor for an LED circuit is the power rating. The power rating indicates how much power the resistor can safely dissipate without being damaged. When connecting a resistor in series with an LED, it is essential to choose a resistor with an appropriate power rating to handle the thermal energy generated as current flows through it. If the power rating is too low, the resistor can overheat and potentially fail, leading to circuit malfunction or damage to the LED.

In an LED circuit, maintaining safe operating conditions is vital to ensure the longevity of the components. Therefore, assessing the voltage drop across the resistor and the current passing through it allows for calculating the power dissipation (using the formula P = I²R or P = V²/R). By ensuring that the resistor's power rating exceeds this calculated power dissipation, you can prevent overheating and ensure stable operation of the LED circuit.