AET Schematic Interpretation 2

Question 1

On a schematic diode symbol, the bar at the tip of the triangle identifies which terminal?

Accepted Answer

Cathode

Answer

The bar marks the cathode, and the triangle points in the direction of conventional current flow.

Question 2

A diode symbol whose cathode bar has small bent ends (Z-shaped) represents which device?

Accepted Answer

Zener diode

Answer

The bent-end cathode bar is the standard symbol for a Zener diode used for voltage regulation.

Question 3

Unless otherwise noted, relay contacts on an aircraft schematic are drawn in which condition?

Accepted Answer

De-energized (coil not powered)

Answer

Relay and switch contacts are conventionally shown in the de-energized, normal (shelf) position.

Question 4

On a schematic, two lines that cross with no dot at the intersection indicate what?

Accepted Answer

The wires are not electrically connected

Answer

A junction dot is required to show a connection; crossing lines without a dot are not connected.

Question 5

What do the dots placed near transformer windings on a schematic indicate?

Accepted Answer

Winding terminals that are in phase with each other

Answer

Dot notation marks terminals of the windings that have the same instantaneous polarity.

AET - Avionics Electronic Technicians Practice Test