Video Notes: Electrical Fundamentals Review (Capacitance, Inductance, Ohm's Law, Batteries)

Vocabulary flashcards covering key concepts from the video notes.

Total capacitance of capacitors in series (0.02 µF, 0.05 µF, 0.10 µF)

0.0125 µF (calculated from 1/C = 1/0.02 + 1/0.05 + 1/0.10)

Mutual inductance basis for transformer operation

Inductance

Converting farads to microfarads

Multiply farads by 10^6

Capacitors in DC circuits are used to

Smooth out slight pulsations in current/voltage

Converting farads to picofarads

Multiply farads by 10^12

Factors that strengthen a coil inductor

Adding coils close together

Electrostatic fields are also known as

Dielectric fields

Effect that does not apply to electron movement in a conductor

Static energy

Voltmeter reading across a closed switch with power on

Zero voltage

Common rectifier component in circuits

Diodes

In a parallel circuit with four 6-ohm resistors on a 24V battery, VR3 is

24 volts

Term for the combined resistive forces in an AC circuit

Impedance

Total inductance in series with non-coupled fields

Equal to the sum of the individual inductances

What increases inductive reactance

Inductance and frequency

Total capacitance in parallel (0.25 µF, 0.03 µF, 0.12 µF)

0.40 µF

Correct way to connect a test voltmeter

In parallel with the unit under test

Meaning of milliampere

0.001 ampere

Voltage drop across each resistor in a 24V parallel circuit with equal resistors

24 volts

Unit for potential difference measured between insulated conductors

Volts

Capacitor capacitance depends on

Plate area and spacing (distance between plates)

AC working voltage rating for a capacitor

At least 50 percent greater than the highest applied voltage

Total capacitance in parallel for .25 µF, .03 µF, and .12 µF

0.40 µF

Most electrical power in a DC parallel circuit example

Two lights at 3 A each in a 24 V parallel system

AC values are assumed to be

Effective values

Opposition to AC by a coil (ignoring resistance)

Inductive reactance

Power dissipated by a 14-ohm resistor in series with 0.05 A

0.035 W (35 milliwatts)

Voltage across parallel loads at 30V source (10W and 20W in parallel)

Voltage across each load is the same; equal to the source voltage (30V)

Charging several aircraft batteries together generally true statements

1 and 2

Rapid charging Ni-Cd batteries method

Constant voltage and varying current

Reason for space beneath plates in a lead-acid battery cell

Prevent sediment buildup from contacting plates and causing a short circuit

Indication of improperly torqued Ni-Cd cell connections

Heat or burn marks on the hardware

Potassium carbonate deposits on Ni-Cd cells indicate

Normal operation

Servicing Ni-Cd and lead-acid batteries in the same area

Contamination of both types would occur

Electrolyte is lowest in Ni-Cd when battery is

In a discharged condition

Why Ni-Cd electrolyte level appears lower during discharge

The electrolyte is absorbed into the plates

Water added to Ni-Cd battery when not fully charged may cause

Excessive spewing during charging

Effect of a rise in Ni-Cd cell temperature

Causes a decrease in internal resistance

Basic unit of voltage

Volt

Basic unit of current

Ampere

Basic unit of resistance

Ohm

Most important electrical law for aircraft mechanics

Ohm’s law

Three elements in Ohm’s law

Voltage, current, and resistance (volts, amps, ohms)

Five sources of electrical energy

Magnetism, chemical energy, light, heat, and pressure

Four factors affecting resistance

Material, cross-sectional area, length, temperature

How to tell resistance of a composition resistor

Color bands on the resistor

Three things every electrical circuit must contain

Source of energy, a load, and conductors to connect them

Basic unit of electrical power in DC

Watt

Hydrometer reading temperature correction for lead-acid electrolyte at 80°F is

No temperature correction required at 80°F

Reason a fully charged lead-acid battery won’t freeze easily

Most of the acid is in the solution

What determines charging current when using a constant voltage source

The ampere-hour capacity of the battery

Polarity of an electromagnet using left-hand rule

Left hand rule: thumb north when fingers follow electron flow

Kilowatt meaning

1,000 watts

What happens to current if voltage increases with constant resistance in DC

Current increases

Three DC circuit types by component placement

Series, parallel, and series-parallel

Ohms in a megohm

One million (1,000,000) ohms

Portion of an amp that is a milliamp

0.001 of an ampere (one thousandth)

Precautions in a shop servicing both lead-acid and Ni-Cd batteries

Keep them separate; do not use the same tools on both types

Thermal switch purpose in electric motors

Open the circuit to allow cooling of the motor

Spilled lead-acid electrolyte procedure

Apply sodium bicarbonate solution then rinse with water

Neutralizing spilled Ni-Cd electrolyte

Boric acid and water solution

Ni-Cd electrolyte highest when battery is

Fully charged condition

Voltage drop depends on

The amperage of the circuit

Effect of removing a bulb in a parallel circuit

Total resistance increases

Transformer ratio and current in a step-up transformer (1:4)

Current is stepped down by a 1 to 4 ratio

What decreases resistance in a conductor

Decrease length or increase cross-sectional area

Resistor value in a 48V, 3-resistor parallel circuit with total power 192W

36 ohms

Forward biasing of a solid-state device

Device conducts

Material through which magnetic lines pass most readily

Iron

Zero voltage reference on a circuit diagram

Ground