Final answer:
The maximum current draw for the overhead garage door motor and lights should not exceed 80% of the circuit breaker's rating for safety reasons. The power dissipated by devices like lightbulbs and motors can be calculated with the power formula P=IV, considering voltage, current, and resistance.
Step-by-step explanation:
The maximum current draw for the overhead garage door motor and lights would be dictated by the specifications and safety regulations related to the electrical circuit in which they are installed. For practical and safety reasons, circuit breakers are designed to allow a continuous use at 80% of their current capacity. If, for example, the breaker is rated at 20 A, then the maximum continuous current draw would be 16 A to prevent overloading the circuit and causing potential hazards. Therefore, the maximum current draw would typically be 80% of the breaker's rating, accounting for both the motor and the lights connected to the same circuit.
When calculating the power dissipated or consumed by an electrical appliance, the power formula P=IV is used, where P is the power in watts, I is the current in amperes, and V is the voltage in volts. For the bulb and motor scenario from the textbook example, one would have to consider the total current and voltage, along with the resistance of the wires and the nominal wattage of the devices, to determine the power dissipation and consumption.