NALMCO Certified Apprentice Lighting Technician (CALT) Practice Exam

On a parallel circuit, if one lamp goes out, what will happen to the other lamp?

1. Fail to light

2. Continue to operate normally

3. Light only dimly

4. Experience severe end blackening

The correct answer is: Continue to operate normally

In a parallel circuit configuration, each component,such as lamps, is connected to the same voltage source independently of each other. This means that each lamp has its own direct path to the power supply. When one lamp goes out, it does not interrupt the electrical current flowing through the other lamps. As a result, the remaining lamps continue to operate normally, provided that they are functioning correctly. This behavior is a defining characteristic of parallel circuits, which contrasts with series circuits where components are interconnected in a single path. In a series circuit, if one component fails or goes out, it breaks the circuit, and all components would cease to operate. Therefore, the correct understanding of a parallel circuit allows us to conclude that the other lamp will continue to function as expected when one lamp is removed or fails.