Electrical Contactors and Relays Quiz

Contactor is a device used to control the flow of electric current in a circuit.

The primary function of an electrical contactor is to control the starting and stopping of electric motors.

Overload relays protect against overcurrent in electrical circuits.

The main function of an auxiliary contact in a contactor or relay is to provide additional switching capabilities.

In a relay, a normally open (NO) contact is open in the resting state, while a normally closed (NC) contact is closed.

The role of the coil in a relay is to generate a magnetic field.

The primary difference between a contactor and a relay lies in their current ratings.

Overload relays are commonly used in motor control circuits to protect against overcurrent.

A 'seal-in' circuit in relays is one that maintains relay operation after the initial actuation.

The 'holding contact' of a contactor in a motor control circuit maintains the contactor coil energized after the start button is released.

A characteristic feature of a magnetic contactor is its use of an electromagnet to control contacts.

The function of a 'control relay' in an electrical system is to control the operation of other devices.

A 'differential relay' in electrical systems is commonly used to detect faults by comparing currents or voltages.

A mercury-wetted relay is typically used in sensitive signal switching applications.

A 'time-delay relay' is primarily used to delay the start of a motor.