Question 1

The simplest way to sum up the operation of the diac is to say it is a voltage-sensitive ____.&#10;A) AC switch&#10;B) triac&#10;C) PNPN&#10;D) SCR

Accepted Answer

The diac is a two-terminal device that can conduct current in both directions when triggered by a voltage above its breakdown voltage. It is commonly used as an AC switch in electronic circuits. Therefore, the diac can be best described as a voltage-sensitive AC switch.

Question 2

The primary function of a diac is to ____.&#10;A) control a large amount of power&#10;B) phase shift a triac&#10;C) furnish a large output pulse&#10;D) phase shift a UJT

Accepted Answer

A diac is a bidirectional device that conducts current in either direction when a certain voltage threshold is reached. Its primary function is to trigger or phase shift a triac, which is a three-terminal device used to control large amounts of power. Therefore, the best choice is B.

Question 3

The diac is a voltage-sensitive switch that can operate on ____.&#10;A) DC only&#10;B) either polarity&#10;C) DC or AC&#10;D) positive resistance

Accepted Answer

The diac is a type of diode that can conduct current once its breakover voltage has been reached, and it can do so in either direction, making it suitable for alternating current (AC) applications. This means it can operate on either polarity of the applied voltage.

Question 4

A diac can be unidirectional or bidirectional.

Accepted Answer

A diac is inherently a bidirectional device, designed to conduct current in both directions once its breakover voltage has been reached.

Question 5

The diac will remain turned on until the applied voltage drops below ____.&#10;A) above its holding current&#10;B) below its holding current&#10;C) above its conduction level&#10;D) below its conduction level

Accepted Answer

The answer of The diac will remain turned on until...

Question 6

The operation of the diac is very different to that of a unijunction transistor.

Accepted Answer

The answer of The operation of the diac is very...

Question 7

There are three schematic symbols for the diac.

Accepted Answer

The diac typically has one standard schematic symbol, which represents a bidirectional trigger device.

Question 8

When voltage is applied to the diac, it will remain in the turned-off state until the applied voltage reaches a predetermined level.

Accepted Answer

A diac is a type of diode that conducts electrical current only after its breakover voltage has been reached momentarily, meaning it stays off until the applied voltage reaches a specific threshold.

Question 9

The break-back voltage of the SBS is more pronounced than that of the diac.

Accepted Answer

The break-back voltage of the SBS is more distinct or noticeable than that of the diac.

Question 10

The diac has the ability to operate in an AC circuit while the ____ is a DC device only.&#10;A) triac&#10;B) thyristor&#10;C) UJT&#10;D) SIDAC

Accepted Answer

The UJT (Unijunction Transistor) is a DC device used primarily for triggering and timing applications, unlike the diac which can operate in AC circuits.

Deck 55: The Diac and SBS