What is the result of opening the holding contact in a motor starter?

Opening the holding contact in a motor starter directly results in the motor stopping. The holding contacts are designed to maintain the circuit closure once the motor has been started. They essentially keep the relay coil energized after the start button is released. When these contacts open, it interrupts the power supplied to the relay coil, leading to the de-energization of the motor circuit. As a result, the motor ceases operations almost immediately, stopping its function.

The other choices are not accurate in this context. A motor restarting immediately would indicate that the holding circuit is still active or that some external control is re-engaging the motor, which is not the case when the holding contact is opened. Describing the motor going into overload implies a scenario where the motor remains energized but is subjected to excessive current, which is unrelated to the state of the holding contact. Lastly, the motor turning off slowly suggests a ramp-down effect, which does not happen simply by opening the holding contact; the motor will stop rather abruptly in this case.