Electronic information (ASVAB FOR DUMMIES)

What are 3 ways in which electricity Is measured?

Volts, Amps, Ohms

What is electrical current?

The flow of electrons moving from one place to another

What does watt measure in electricity

Power ;the rate at which electrical energy is consumed or transformed into another type of energy

What is a watt-hour?

A watt-hour is an amount of electrical energy used and relates power (watts) and time (hour).

What are the smallest particles that can be broken up without losing their original properties

Atom

What 2 types of subatomic particles are in an atoms nucleus?

Protons and neutrons

What type of charge do electrons have?

Negative

What does substance atomic number tell you?

How many protons are in the substance

What do number of electrons in a valance shell determine ?

Whether an object is conductor, semiconductor, or insulator

What happens with electrons in a conductor?

flow freely between different atoms.

What happens with electrons in an insulator?

Electrons don't have much room to move in an insulator. That's because an insulator has a mostly full valence shell.

What is a circuit?

Path of electrical current

What tools can measure voltage in a circuit?

Voltmeter or multimeter

What is an electrical storage compartment in a battery called?

Cell

How is electrical current (the flow of electrons) expressed?

in amperes (amps) which represent a charge (in coulombs) over a second.

What is a circuit breaker?

- a device which stops the current flowing in a circuit when the current is too high

Rheostat

Vary the resistance against a current flow without opening a circuit

What is ohms law?

The current in a circuit is equal to the applied voltage and inversely proportional to the circuit resistance

How do you express ohms law in mathematical terms?

V=IR

I=V/R

R=V/I

Most electrons will take path of lower resistance, but some will still take a path of higher resistance.

True

What is a load in terms of electricity?

a source of resistance that converts electrical energy into another form of energy (like a lightbulb).

What happens to the electrical current if you flip a light switch from "On" to "Off"?

Circuit opens to interrupt the flow of electrical current. As a result the light turns off

What does a fuse do?

It breaks the circuit if there is a fault (you can’t replace)

When can current flow through an insulator, such as air?

if there's enough difference of potential, such as when lightning travels through the air to strike something on Earth's surface.

How many paths are there for an electrical current in single series circuit?

One

How are loads wired in a parallel circuit?

Each load is wired along its own path

What happens if there is a break in an electrical current path in a series circuit?

The electrical flow stops everywhere in the circuit

What happens if there is break in an electrical current path in a parallel circuit?

The current flow stops in the path with a break; it continues to flow to other loads

What happens to the total resistance of a current if you add a load in parallel?

decreases the total resistance of a current because it provides an additional pathway for electrons to take.

What is the most common circuit configuration for a homes electrical system?

Most homes are wired with series-parallel circuits.

What is a short circuit?

A connection that allows current to take the path of least resistance

In a wire where are the magnetic lines of force?

perpendicular to the conductor and parallel to each other

In how many directions can direct current flow?

One

alternating current constantly changes direction in a regular path?

True

What type of current enters your home from the power company?

Alternating current (AC)

What does a grounding wire do?

gives excess electricity a place to go when it's displaced from its original path.

What is the measure for the number of times an alternating current changes direction in one second?

is known as its frequency, which is measured in Hertz (Hz).

What is capacitive reactance?

The opposition of AC current flow caused by a capacitor.

What is inductive reactance?

Opposition to current flow in a circuit due to induction.

How can you express impedance in mathematical terms?

Impedance = Electromotive force / Current

What does a capacitor do?

stores or holds a charge of electrons.

What is a semiconductor diode?

A semiconductor diode is a component made of a material with conductivity somewhere between that of a conductor and an insulator.

What does a rectifier do?

Changes AC to DC

Three basic terminals on transistor?

emitter, base, collector

What function do wires perform in electrical system ?

Pass current

Transducer

converts energy from one form to another

Inductor

A coil of wire that creates a magnetic field when current passes through it

What numbers do 🔴 markings represent on nonverbal resistors?

Black= 0

Brown= 1

Red= 2

What is a pontentiometer?

Variable resistor

Diode

Allows current to flow in only one direction

What does circuit diagram show you?

How the components in a circuit are connected together

What color are positive DC wires?

Red

What color are negative DC wires?

Black

What color are DC ground wires?

White or grey

Can green wires be live?

Yes

What should you assume about electrical wires ?

They are all live

Which way does current hold?

Negative to positive

Symbol of ohms

Ω

Which object supplies the LEAST resistance to an electrical current: wood, rubber or copper?

Copper

What units are used to measure the rate of electrons moving through a conductor?

Amperes

If a diagram mentions 55 cycles per second, what is its equivalent in hertz?

55 because Cycles per second is the same thing as hertz, so 55 cycles per second equals 55 Hz.

What is electric resistance?

Opposition to the flow of current

What is electrical potential?

Voltage

What is the unit you use to measure electrical charge transported by current of one ampere in one second?

Coulomb

What measures current in a circuit?

Ammeter

What is electromotive force

voltage (same thing as electrical potential)

EMF stands for what?

electromotive force

What type of device would you use to reduce the current in an electrical circuit?

Resistor

Transistor (semiconductor)

amplify signals

A number of-12 wire, compared to a number-6 wire,

Smaller In diameter (the larger the number, the smaller the diameter of the wire)

Electrical current flows with

Voltage source (such as battery)

Load (which is a source of a resistance)

Conductors (carry current)