What is the recommended method to discharge a capacitor?

The recommended method to discharge a capacitor involves using a resistor, specifically one that is within the range of 15,000 to 20,000 ohms and rated for 2 to 5 watts. This method is safe and effective because it allows the stored electrical energy in the capacitor to be released gradually, minimizing the risk of a sudden discharge that could cause damage or injury.

Using a resistor provides a controlled way to discharge the capacitor while limiting the current flow, preventing a potentially dangerous spike that could occur if a direct short-circuit were applied, such as with a screwdriver. The resistor dissipates the energy as heat in a controlled manner, which reduces the chances of damaging the capacitor or causing arcing.

The other methods listed are unsafe. Tapping the terminals with a hammer can lead to physical damage to the capacitor or risking an uncontrolled discharge. Submerging a capacitor in water is both ineffective and extremely hazardous, as it could lead to short circuits or even electrical shock. Therefore, using a resistor is not only the safest but also the most effective method for discharging a capacitor.