Schematic Representation

Why are automatic-reset circuit breakers not allowed in aircraft?

They may repeatedly energize a faulted circuit and create fire risk

In a schematic, what does a dashed line typically represent during an aircraft modification?

Existing wire prior to modification

Which factor primarily determines the resistance value in a carbon composition resistor?

Ratio of graphite to insulating filler

What is the distinguishing feature of a tapped wire-wound resistor?

It can be adjusted at installation

What does the tolerance band on a resistor indicate?

Allowed variation from the stated resistance value

What is the primary function of a resistor in an aircraft circuit?

Limit current flow

A photoconductive cell's resistance changes primarily due to:

Ambient light intensity

In film resistors, what purpose does the ceramic rod serve?

Provides a substrate for resistive material deposition

A resistor has three color bands only. What tolerance is implied?

20%

What does Kirchhoff's Voltage Law state about a closed loop?

The algebraic sum of all voltages equals zero

Why are professional wiring practices required to mark installed wires?

To aid troubleshooting and future modifications

What differentiates a current limiter from a fuse?

It tolerates short overloads before opening

Which resistor type decreases resistance as temperature increases?

Thermistor

What is the primary role of a relay in an electrical circuit?

To control large current with a small control current

When using crossover symbols, why is it important to match version A or version B consistently throughout a schematic?

To prevent technician confusion

Which variable resistor type is designed to vary current specifically?

Rheostat

Why is a direct short particularly dangerous in aircraft wiring?

It provides an almost resistance-free path for current

In a series circuit, why is the current the same at all points?

Current has only one path to flow through

When using a potentiometer as a voltage divider, what does the wiper determine?

The voltage applied across the load

Why is alternating current preferred in aircraft power systems for many devices?

Transformers make AC transmission practical and efficient

A gold third band on a resistor indicates what adjustment?

Multiply the first two digits by 10%

Which protective device must always be replaced after opening?

Fuse

Why are wire-wound resistors typically used in aviation circuits?

They handle large amounts of current with high power ratings

What condition causes a thermal protector to open?

Motor overheating

Why should potentiometer resistance typically be much larger than the load resistance?

To minimize wasted current as heat