What safely discharges electrical energy from a capacitor?

The safest way to discharge electrical energy from a capacitor is by using a resistor, such as a 10k ohm resistor. When a capacitor is charged, it holds a significant amount of electrical energy, which can be very dangerous if discharged quickly or improperly.

Using a resistor allows for a controlled discharge of the capacitor's stored energy. The resistor limits the current flow, reducing the risk of damage to the capacitor or creating a spark, which could lead to hazardous situations. The value of 10k ohms provides a balance between sufficiently discharging the capacitor over a reasonable amount of time while minimizing the risk of high current levels.

Other components like fuses, diodes, or relays are not appropriate for this function. Fuses are designed to protect circuits by breaking the circuit under excessive current, but they do not provide a means for safe discharge. Diodes can allow current to flow in one direction but do not serve the purpose of discharging a capacitor safely. Relays are electrically operated switches that can control circuits but do not discharge capacitors either. Thus, using a resistor is the most effective and safest method for discharging a capacitor's energy.