If the brake contact E fails to open when the brake coil is energized, what will occur?

When the brake contact fails to open while the brake coil is energized, the current flowing through the brake coil remains unchanged. The reason for this lies in the operation of the brake system. Normally, when a brake contact opens, it interrupts the circuit to the brake coil, leading to a reduction in current and allowing the system to release the brake. However, if the contact does not open, the circuit remains closed, and the current continues to flow as it did before the failure occurred.

This situation indicates that the brake coil will maintain its current state because the electrical path through the brake contact is still intact. Any attempts at stopping or resetting the system would not take effect because the brake mechanism is still engaged, allowing the current to continue without interruption.

Thus, the correct answer highlights that the system's behavior remains constant in terms of current through the brake coil when the brake contact fails to open, which is the crux of how electrical systems function in the presence of faults.