Which of the following could be a method of deenergizing a seal-in circuit?

A stop pushbutton is a common method used to deenergize a seal-in circuit. Seal-in circuits are designed to maintain their energized state even after the initial activating signal is removed, thereby requiring a specific method to deactivate them. The stop pushbutton serves this purpose by interrupting the circuit, allowing it to break the seal and thus stop the motor or control process connected to the system.

In this context, pressing the stop pushbutton opens the circuit, effectively removing the energy supplied to the seal-in circuit. This is crucial for ensuring safety and control within motor operations, as it provides a straightforward and immediate means to halt progress or respond to emergencies.

While a timer could regulate the duration of energy supplied to the circuit, it doesn't specifically deenergize it on demand. Removing the power source, while it would certainly stop the circuit, is not a practical control method and may not always be readily available or safe. Adding a resistor typically does not serve to deenergize the circuit, but rather can affect the circuit characteristics, such as current flow, without shutting it down entirely. Hence, the use of a stop pushbutton stands out as the most effective and intentional method for deenergizing a seal-in circuit.