1.
What is the part of the PLC called where inputs and outputs are connected?
Correct Answer
B. Input/output interface
Explanation
The part of the PLC where inputs and outputs are connected is called the input/output interface. This interface allows the PLC to receive signals from external devices as inputs and send signals to external devices as outputs. It acts as a bridge between the PLC's internal processing unit and the external devices, enabling communication and control between them.
2.
Where does PLC stores its program?
Correct Answer
D. Memory
Explanation
PLC stores its program in memory. Memory is a crucial component of a PLC as it holds the instructions and data necessary for the PLC to execute its program. The program is stored in non-volatile memory, which means that it is retained even when power is lost. This allows the PLC to resume its operation and continue executing the program once power is restored. Storing the program in memory ensures that it can be easily accessed and modified as needed.
3.
Which of the following is a PLC input device?
Correct Answer
C. Sensor
Explanation
A sensor is a PLC input device because it is used to detect and measure physical quantities or environmental conditions such as temperature, pressure, proximity, or light. Sensors provide input signals to the PLC, which can then process the information and make decisions based on the input received.
4.
Which of the following is NOT part of a basic PLC system?
Correct Answer
A. Relay box
Explanation
A relay box is not part of a basic PLC system because it is not a component that is typically included in the basic setup. A basic PLC system consists of a power supply to provide electrical power, memory to store the program and data, and a CPU (Central Processing Unit) to execute the program and control the inputs and outputs. The relay box, on the other hand, is a separate device used to interface the PLC with external devices such as sensors and actuators. While it is commonly used in PLC systems, it is not considered a fundamental component of the basic setup.
5.
Which of the following is an output device?
Correct Answer
D. Motor
Explanation
A motor is an output device because it is responsible for producing physical movement or action based on the input it receives. In this case, the motor is able to convert electrical energy into mechanical energy, which allows it to perform tasks such as spinning, rotating, or moving objects.
6.
A PLC is a computer used for industrial automation.
Correct Answer
A. True
Explanation
A PLC (Programmable Logic Controller) is indeed a computer used for industrial automation. It is designed to perform specific tasks and control machinery or processes in industries. PLCs are programmed to monitor inputs, make decisions based on the programmed logic, and control outputs accordingly. They are widely used in various industries such as manufacturing, oil and gas, power plants, and transportation, to automate and control different processes. Therefore, the statement "A PLC is a computer used for industrial automation" is true.
7.
Which of the following is the application of PLC?
Correct Answer
D. All of the above
Explanation
PLC, or Programmable Logic Controller, is a computerized control system that is widely used in industrial automation. It is used to control and monitor various processes and machinery in different applications. In this case, all the options mentioned - vending machines, automatic doors, and cereal filling systems - can be automated and controlled using PLCs. Therefore, the correct answer is "All of the above."
8.
Which of the following is an example of discrete (digital) control?
Correct Answer
A. Turning a lamp ON or OFF
Explanation
Turning a lamp ON or OFF is an example of discrete (digital) control because it involves a binary decision - the lamp can either be ON or OFF. There are no intermediate levels of brightness or volume, or varying speeds involved in this control. It is a simple on/off switch, making it a discrete control.
9.
What are solenoids, lamps, and motors connected to?
Correct Answer
D. Digital output
Explanation
Solenoids, lamps, and motors are typically connected to Digital Output. Digital output signals control these devices by providing binary signals (on/off or high/low), which are suitable for controlling the operation of solenoids, lamps, and motors in various electronic systems.
10.
Gear Box is used to decrease the speed and increase the torque.
Correct Answer
A. True
Explanation
The statement is true because a gear box is a mechanical device that is used to transmit power from an engine to the wheels of a vehicle. It consists of a series of gears that can be shifted to different ratios, allowing the engine to operate at different speeds while maintaining the desired torque output. By decreasing the speed and increasing the torque, a gear box helps to optimize the performance and efficiency of the engine in various driving conditions.