Question 1

Relays that use an optical coupling are referred to as being ____.&#10;A) optoisolated&#10;B) electrically isolated&#10;C) mechanically insulated&#10;D) mechanically bound

Accepted Answer

Optoisolated relays use an optical coupling mechanism to provide electrical isolation between the input and output, hence the term "optoisolated."

Question 2

The greatest disadvantage of the solid-state relay is the fact that the control input voltage is isolated from the line device the relay is intended to control.

Accepted Answer

The greatest disadvantage of solid-state relays is not the isolation between control input voltage and the line device, but rather their tendency to fail in a closed (on) position, which can lead to uncontrolled power flow to the device they are supposed to control. The isolation between control and load circuits is actually one of the advantages of solid-state relays, providing safety and reducing electrical noise in the control signals.

Question 3

The MOV is a ____ device meaning that it can conduct current in either direction.&#10;A) unidirectional&#10;B) bilateral&#10;C) multiphase&#10;D) multimode

Accepted Answer

The MOV (Metal Oxide Varistor) is a bilateral device, meaning it can conduct current in both directions when the voltage exceeds a certain threshold.

Question 4

If the solid-state relay is designed to control a DC load, a ____ connects the load to the line.&#10;A) power inverter&#10;B) power rectifier&#10;C) power transistor&#10;D) power transformer

Accepted Answer

A power transistor is used in solid-state relays designed to control DC loads because it can efficiently switch the DC current on and off to the load.

Question 5

The ____ has no moving parts, is resistant to shock and vibration, and is sealed against dirt and moisture.&#10;A) mechanical relay&#10;B) solid-state relay&#10;C) optical relay&#10;D) hybrid relay

Accepted Answer

Solid-state relays have no moving parts, making them resistant to shock and vibration. They are also sealed against dirt and moisture, which makes them reliable in harsh environments. Unlike mechanical relays, solid-state relays use semiconductor devices to perform their switching functions.

Question 6

The control voltage for most solid-state relays ranges from about 3 to 32 volts and can be direct current or alternating current.

Accepted Answer

Solid-state relays (SSRs) are designed to be controlled by a low voltage signal, which can indeed range from about 3 to 32 volts and can be either direct current (DC) or alternating current (AC), making them versatile for various applications.

Question 7

Solid-state relays can be used to control either a DC or an AC load.

Accepted Answer

Solid-state relays (SSRs) are designed to switch either AC or DC loads, making them versatile for various applications by using different internal circuitry tailored for the specific type of load.

Question 8

Solid-state relays intended for use as AC controllers have a ____ connected to the load circuit.&#10;A) diac&#10;B) semiconductor&#10;C) power transistor&#10;D) triac

Accepted Answer

Solid-state relays intended for use as AC controllers typically have a triac connected to the load circuit. Triacs are able to control power flow to AC loads and are suitable for switching applications.

Question 9

MOVs are typically connected across the coils of relays and starters in motor control systems to help prevent voltage spikes.

Accepted Answer

Metal Oxide Varistors (MOVs) are used across the coils of relays and starters in motor control systems to absorb and dissipate voltage spikes, protecting the system from transient overvoltages.

Question 10

MOVs are extremely slow acting.

Accepted Answer

Metal Oxide Varistors (MOVs) are actually very fast-acting surge protection devices, responding to over-voltages in nanoseconds.

Deck 27: The Solid State Relay