Which statement describes solid state DC output modules?

Which statement describes solid state DC output modules?

• A. They can only switch AC.
• B. They use transistors as switches; circuit closes when transistor conducts.
• C. They require no supply voltage.
• D. They use mechanical relays.

Answer: (B)

Solid state DC output modules control a load using semiconductor switches instead of moving parts. They rely on transistors as the switching elements; when the control signal turns the transistor on, it conducts and the circuit is closed, letting current flow through the load. Because there are no mechanical contacts, switching is fast and the device has no wear from movement, which is a key advantage of solid-state outputs. This approach is suitable for DC, using transistors to turn the current path on or off. Other statements don’t fit because solid-state outputs do require a drive or supply to turn the transistor on, they are not limited to switching AC only, and they do not use mechanical relays.

Solid state DC output modules control a load using semiconductor switches instead of moving parts. They rely on transistors as the switching elements; when the control signal turns the transistor on, it conducts and the circuit is closed, letting current flow through the load. Because there are no mechanical contacts, switching is fast and the device has no wear from movement, which is a key advantage of solid-state outputs. This approach is suitable for DC, using transistors to turn the current path on or off.

Other statements don’t fit because solid-state outputs do require a drive or supply to turn the transistor on, they are not limited to switching AC only, and they do not use mechanical relays.