Which relay contact configuration is held open by a spring?

Which relay contact configuration is held open by a spring?

• A. Normally Closed
• B. Normally Open
• C. Relays
• D. Micro Switch

Answer: (B)

Relays bias their contacts with springs to define the default state. A normally open contact is kept open by its spring when the coil is not energized, so no current flows until the coil is energized. When you apply power to the coil, the magnetic force pulls the contact closed, completing the circuit. This is why the spring-hold-open configuration describes the normally open arrangement. If it were the other way around, a normally closed contact would be held closed by the spring and would open when energized. The other terms point to device types rather than a specific contact state: a relay is the overall device, and a micro switch is a type of switch that can employ NO or NC contacts.

Relays bias their contacts with springs to define the default state. A normally open contact is kept open by its spring when the coil is not energized, so no current flows until the coil is energized. When you apply power to the coil, the magnetic force pulls the contact closed, completing the circuit. This is why the spring-hold-open configuration describes the normally open arrangement. If it were the other way around, a normally closed contact would be held closed by the spring and would open when energized. The other terms point to device types rather than a specific contact state: a relay is the overall device, and a micro switch is a type of switch that can employ NO or NC contacts.