Question 1

Control magnetic relays are used to control small loads.

Accepted Answer

Control magnetic relays are designed to control small loads such as lights, fans, solenoids, and motors. Control magnetic relays are used for controlling small loads like lights, fans, motors, etc.

Question 2

Solid-state relays generally apply 3 to volts DC to the input to control the operation of the relay.&#10;A)12&#10;B)22&#10;C)32&#10;D)42

Accepted Answer

C

Question 3

Relays are used more often to open and close control circuits than to operate power circuits.

Accepted Answer

Relays are typically used to control smaller signals and control circuits, rather than directly operating high-power equipment. Relays are commonly used for controlling circuits in applications such as industrial automation, HVAC systems, and motor control. They are less commonly used for operating power circuits.

Question 4

Starters, contactors, and are similar in construction and operation.&#10;A)mechanical thermostats&#10;B)symbols&#10;C)breakers&#10;D)relays

Accepted Answer

Starters, contactors, and relays are similar in construction and operation as they all use electromagnetic forces to control the switching of electrical circuits. They all have a coil that creates a magnetic field to pull in a contact or set of contacts to make or break a circuit. Mechanical thermostats and breakers, on the other hand, do not use electromagnetic forces and have different construction and operation. Starters, contactors, and relays are all electromagnetic switching devices that use a solenoid to control the operation of an electrical circuit. They all work by energizing the solenoid coil, which then moves a set of contacts to open or close the circuit. Mechanical thermostats and symbols are not similar in construction or operation to starters, contactors, or relays. Breakers, while also used for circuit control, are different in construction and function as they trip in response to overcurrents in a circuit to protect against damage.

Question 5

The greatest advantage of relays with mechanical contacts is that they are resistant to shock and vibration.

Accepted Answer

Relays with mechanical contacts are susceptible to wear and tear, and their performance can be affected by shock and vibration, unlike solid-state relays which have no moving parts and are more resistant to such physical disturbances.

Question 6

Most of the relays used in machine tool control have double-break contacts.

Accepted Answer

Double-break contacts provide two separate contact points for each pole, allowing for improved reliability and reduced contact wear. This is important in machine tool control applications where precise and reliable operation is necessary. Most relays used in machine tool control have double-break contacts, which means that each contact can open and close two separate circuits. This allows for greater flexibility and precision in controlling the machine tool.

Question 7

When the moving element of the thermostat control touches the closed contact, the relay closes and .&#10;A)is held in this position by a maintaining contact&#10;B)handles the current to a starter coil&#10;C)causes the relay to freeze&#10;D)the current flow bypasses the operating coil

Accepted Answer

When the moving element of the thermostat control touches the closed contact, the relay closes and is held in this position by a maintaining contact. This allows the current to flow to the controlled device until the moving element moves away from the closed contact, causing the relay to open again. When the relay is closed by the moving element of the thermostat control touching the closed contact, it is held in this position by a maintaining contact. This means that the relay will remain closed even after the moving element of the thermostat control returns to its initial position.

Question 8

Solid-state relays intended to control the operation of AC loads use an electronic device called a to connect the load to the line.&#10;A)diac&#10;B)triac&#10;C)thyristor&#10;D)transducer

Accepted Answer

Triacs are commonly used in solid-state relays for AC loads as they are able to control the flow of both positive and negative current. Diacs and thyristors are also electronic devices used in AC circuits, but they are not typically used in solid-state relays for controlling AC loads. Transducers are devices used to convert one form of energy into another and are not used for switching AC loads. Solid-state relays for AC loads typically use a triac as the electronic switch device. A diac is a trigger device used to control the firing of a triac, while a thyristor is a broader category of semiconductor devices that includes the triac as well as others such as SCR and GTO. A transducer is a device that converts one form of energy to another and is not typically used as an electronic switch for controlling AC loads.

Question 9

One method of eliminating noise and voltage spikes is to use a .&#10;A)transient suppressor&#10;B)semiconductor&#10;C)temperature-sensitive resistor&#10;D)transducer

Accepted Answer

A transient suppressor is specifically designed to suppress voltage spikes and transient events, making it the best choice for eliminating noise and voltage spikes. Semiconductors, temperature-sensitive resistors, and transducers may have secondary functions that could assist in reducing noise or voltage spikes, but they are not specifically designed for this purpose. A transient suppressor (or surge protector) is specifically designed to eliminate voltage spikes or surges in an electrical circuit. It works by diverting excess voltage away from the circuit to ground, thus preventing damage to the circuit components. A semiconductor or temperature-sensitive resistor may help in reducing noise, but they are not specifically designed for surge protection. A transducer, on the other hand, is a device that converts one type of energy to another, such as sound to electrical signals or mechanical motion to electrical signals, and is not relevant to eliminating noise or voltage spikes.

Question 10

Magnetic relays are affected by the electric noise and the voltage spikes induced in the system.

Accepted Answer

The answer of Magnetic relays are affected by the electric...

Deck 7: Relays