In a series-regulated power supply, the power dissipation of the pass transistor is:

To understand power dissipation in a series-regulated power supply, you can use the standard power formula: Power (P) = Voltage (V) multiplied by Current (I). In this circuit, the voltage dropped across the pass transistor is the difference between the unregulated input voltage and the regulated output voltage (the input/output voltage differential). The current flowing through the pass transistor is essentially the load current. Therefore, the power dissipated as heat by the transistor is P = (Vin - Vout) x I_load. This means the power dissipation is directly proportional to both the load current and the voltage differential across the transistor. Distractors suggesting an 'inverse' or 'indirect' relationship are mathematically incorrect, as increasing either the load current or the voltage drop will increase the heat generated by the component.