Elevator Mechanic Practice Exam

How much resistance is typically measured over a normally closed switch?

1. 0 ohms

2. 1.2 ohms

3. 2.4 ohms

4. 4 ohms

The correct answer is: 0 ohms

In a normally closed switch, when the switch is in its resting state (which is closed), the circuit is complete, allowing current to flow. Therefore, the resistance across the terminals of the switch should be very low, ideally around 0 ohms. This low resistance indicates that the switch is functioning correctly without any significant obstruction to the flow of electricity. Higher resistance values, as indicated in the other options, would suggest that there might be an issue with the switch, such as wear or dirt causing a poor connection. Thus, measuring about 0 ohms confirms that the switch is indeed closed and operational.