An electromechanical relay includes which of these components?

An electromechanical relay functions as a switch that is operated by an electromagnetic force. It typically consists of several key components that enable its operation. Among these components are normally open (NO) contacts, normally closed (NC) contacts, and a solenoid coil.

The solenoid coil is responsible for creating a magnetic field when electrical current flows through it. This magnetic field then moves an armature that can mechanically open or close the contacts. The NO contacts allow electrical current to flow only when the relay is activated, while the NC contacts allow current to flow when the relay is not energized. This dual functionality is essential for various applications where control over electrical circuits is necessary.

By including both types of contacts—NO and NC—the relay offers versatility. This makes it capable of managing complex control tasks in circuits, as it can either establish or interrupt a connection based on the state of the solenoid coil. This is crucial in applications requiring safety mechanisms, circuit protection, and automation, where both options are often needed.

The presence of just one type of contact or an incomplete set of components would limit the functionality of the relay, making it less effective and versatile compared to the configuration that includes both NO and NC contacts along with the solenoid coil.