NCCER Electrical level 2 Module 11
'Control Systems and Fundamental
Concepts' Questions and Answers |
Latest Version | 2024/2025 | 100%
Verified
What is a control system in an electrical context?
✔✔A control system is a set of devices or mechanisms used to regulate or manage electrical
circuits, ensuring that a system operates as intended.
What is the main function of a relay in control systems?
✔✔A relay acts as a switch that opens or closes electrical contacts in a circuit based on an input
signal, often used to control larger loads with smaller control signals.
How does a contactor differ from a relay in control systems?
✔✔A contactor is designed to handle larger currents and is typically used for switching heavy-
duty loads like motors, while a relay is used for controlling smaller loads.
What is the purpose of a control transformer?
1
,✔✔A control transformer steps down the voltage to a safer and lower level for the control
circuit, providing proper voltage for relays, contactors, and other control devices.
What is a programmable logic controller (PLC)?
✔✔A PLC is a digital computer used for automation of industrial processes, such as controlling
machinery, processes, or factory assembly lines.
What is the role of sensors in a control system?
✔✔Sensors monitor physical conditions, like temperature, pressure, or position, and send
feedback to the control system to regulate operations accordingly.
How do push buttons function in electrical control systems?
✔✔Push buttons are simple control devices that can start or stop a process or operation when
pressed, often used for initiating or stopping circuits.
What is the function of a limit switch in control systems?
✔✔A limit switch detects the physical movement or position of a machine or component and
sends signals to the control system to stop, start, or change the operation.
2
, What is the difference between an open and closed loop control system?
✔✔In an open-loop control system, there is no feedback to adjust the output, while in a closed-
loop system, feedback is used to adjust the input and ensure the desired output is achieved.
What are the components of a basic control system?
✔✔The basic components include a power supply, controllers (like PLCs or relays), actuators
(such as motors), and sensors for feedback.
Why is an overload relay important in motor control circuits?
✔✔An overload relay protects motors from damage by disconnecting power if the motor draws
too much current, preventing overheating and failure.
How does a control system improve the efficiency of industrial operations?
✔✔A control system automates processes, reduces human error, ensures consistency, and
optimizes resource use, leading to improved productivity and efficiency.
What is a time delay relay and how is it used in control systems?
✔✔A time delay relay introduces a delay before activating or deactivating a circuit, useful for
applications where a delay in operation is required.
3
'Control Systems and Fundamental
Concepts' Questions and Answers |
Latest Version | 2024/2025 | 100%
Verified
What is a control system in an electrical context?
✔✔A control system is a set of devices or mechanisms used to regulate or manage electrical
circuits, ensuring that a system operates as intended.
What is the main function of a relay in control systems?
✔✔A relay acts as a switch that opens or closes electrical contacts in a circuit based on an input
signal, often used to control larger loads with smaller control signals.
How does a contactor differ from a relay in control systems?
✔✔A contactor is designed to handle larger currents and is typically used for switching heavy-
duty loads like motors, while a relay is used for controlling smaller loads.
What is the purpose of a control transformer?
1
,✔✔A control transformer steps down the voltage to a safer and lower level for the control
circuit, providing proper voltage for relays, contactors, and other control devices.
What is a programmable logic controller (PLC)?
✔✔A PLC is a digital computer used for automation of industrial processes, such as controlling
machinery, processes, or factory assembly lines.
What is the role of sensors in a control system?
✔✔Sensors monitor physical conditions, like temperature, pressure, or position, and send
feedback to the control system to regulate operations accordingly.
How do push buttons function in electrical control systems?
✔✔Push buttons are simple control devices that can start or stop a process or operation when
pressed, often used for initiating or stopping circuits.
What is the function of a limit switch in control systems?
✔✔A limit switch detects the physical movement or position of a machine or component and
sends signals to the control system to stop, start, or change the operation.
2
, What is the difference between an open and closed loop control system?
✔✔In an open-loop control system, there is no feedback to adjust the output, while in a closed-
loop system, feedback is used to adjust the input and ensure the desired output is achieved.
What are the components of a basic control system?
✔✔The basic components include a power supply, controllers (like PLCs or relays), actuators
(such as motors), and sensors for feedback.
Why is an overload relay important in motor control circuits?
✔✔An overload relay protects motors from damage by disconnecting power if the motor draws
too much current, preventing overheating and failure.
How does a control system improve the efficiency of industrial operations?
✔✔A control system automates processes, reduces human error, ensures consistency, and
optimizes resource use, leading to improved productivity and efficiency.
What is a time delay relay and how is it used in control systems?
✔✔A time delay relay introduces a delay before activating or deactivating a circuit, useful for
applications where a delay in operation is required.
3
