Basic Electricity 1st TEST (AMT 5 & 6)

Materials which oppose the movement of electrons are called _________________

insulators.

When electrons flow in a conductor, they cause a(n) _______________ to surround the conductor.

magnetic field

An atom having fewer electrons than protons will carry a ______________ charge.

Positive

_______________ circuit breakers will open the circuit irrespective of the position of the operating control.

Trip-free

Materials which permit the flow of electrons are referred to as _______________

conductors.

The strength of an electromagnet is determined by the ___________________ and by the ______________ flowing thorough it.

number of turns, amount of current

If there is an interruption, or break, in an electrical circuit, it is said to be _____________

open.

The ease with which lines of magnetic flux can pass through a material is known as a material's ___________________

permeability.

If there is a path from one terminal of the source to the other, without passing through the load, the circuit is said to be _____________

shorted.

A DPDT switch will control ______ circuits, and it has either ______ or ______ positions.

2, 2, 3

a 60-watt light bulb installed in a 25-volt circuit will cause how much current to flow?

2.5 amps

_____________________ is the opposition to the flow of magnetic force.

Reluctance

___________ ____________ is the magnetism remaining in a material after the magnetized force has been removed

Residual magnetism

______________ is the ability of a material to retain magnetism after a magnetizing force is removed.

Retentivity

A variable resistor having two terminal is called a

Rheostat

Divide using powers of ten: a. 326,000,000 / 1,900,000 = b. 365,000 / 0.025 = c. 5,400 / 18 =

a. 1.72 X 10 2 b. 1.46 X 10 7 c. 3 X 10 2

Multiply and express your answers in scientific notation: a. 325,000,000 X 1,500,000 = b. 0.000,002 X 45 = c. 750 X 0.25 =

a. 4.87 x 10 14 b. 9 X 10 -5 c. 1.875 X 10 2

Aircraft circuit breakers may operate on what two principles? a. _________________ b. _________________

a. Thermal b. Magnetic

There are two types of electromagnets used in practical applications, those having __________ cores and those having __________ cores.

fixed, movable

One ____________ represents a magnetic flux density of one maxwell per square centimeter.

gauss

The ___________ is the standard unit of electrical resistance, or opposition to current flow.

ohm

An atom having more electrons than protons will carry a _____________ charge.

Negative

What is the resistance of these two composition resistors? (fig.) a. ________ ohms +- ________% b. ________ ohms +- ________%

a. 2.2kΩ, 20% b. 1 MΩ, 10%

Each unit of electrical measurement may be expressed using a single letter.What letters are used for the expressions bellow? a. Voltage b. Current c. Resistance d. Power

a. E (or V) b. I c. R d. P

The resistance of a conductor is affected by what three factors? a.______________ b. _____________ c. _____________

a. Physical characteristics b. Dimensions c. Temperature

Name the three components needed to complete an electrical circuit. a. ______________ b. ______________ c. ______________

a. Power Source b. Conductor c. Load

When one coulomb of electrons flows past a point in one second, there is a current flow of one _____________

ampere.

Using a soft iron core in an electromagnet increases its strength because it ______________ the lines of flux.

concentrates

The ____________ is the basic unit of electrical quantity and is equal to 6.28 billion billion electrons.

coulomb

According to the left-hand rule, the lines of flux would encircle the conductor as shown in ________

B

A charged atom is known as a(n) ______________

Ion

Name five ways electrical energy may be generated.

a. Chemical b. Pressure c. Light d. Magnetic e. Thermal

Static dischargers on an aircraft control surface provide sharp points from which a static charge can be dissipated from the control surface into the ____________

air.

Write the following numbers using metric prefixes: a. 126,000,000 ohms b. 0.002 amp c. 156,000 volts d. 0.000,000,000,002 farads e. 115,900,000 hertz f. 326,000 meters

a. 126 MΩ b. 2 mA c. 156 KV d. 2 pF e. 115.9 MHz f. 326 Km

What is the total power and total current for a 12-volt aircraft system with the following equipment installed: a. Navigation lights, 3 lights and 20 watts each=_____amps b. Radio #1, 60 watts = _____amps c. Radio #2, 30 watts =_____amps d. Interior lights, 30 watts = _____ amps Total power = ______ watts Total current = ______amps

a. 5 b. 5 c. 2.5 d. 2.5 Total power = 180 watts Total current = 15 amps

Write the formula that may be used to find the value in the left column with the values in the center column. Find When These are Known a. Voltage Current and Resistance b. Current Voltage and Resistance c. Resistance Voltage and Current d. Power Voltage and Current e. Voltage Power and Current f. Current Power and Voltage g. Power Resistance and Current h. Voltage Resistance and Power i. Current Power and Resistance j. Resistance Power and Voltage k. Resistance Current and Power l. Power Voltage and Resistance

a. E= IR b. I=E/R c. R=E/I d. P=IV e. V=P/I f. I=P/V g. P=I^2 R h. V=SQR(RP) i. I=SQR(P/R) j. R=V^2/P k. R=P/I^2 l. P=V^2/R

A material is said to have a positive temperature coefficient of resistance if its resistance _______________ as its temperature increases.

increases

A body having an accumulation of electrons on its surface is said to have a ________________ static charge.

negative

Electron flow is considered to be from the _________________ terminal of the battery (or other current source) through the circuit, and return to the _____________ terminal of the battery.

negative, positive

According to the left-hand rule for electromagnets, the pole at end A of the electromagnet is the _____________ pole.

north

The lines of magnetic flux are considered to leave the _____________ pole of a magnet and enter at the _________ pole.

north, south

A ______________ may be used as a voltage divider.

potentiometer

A glass tubular fuse that uses a small spring to pull the fusible link apart is called a _______________ fuse.

slow blow

An electromagnetic switch having a movable core is called a ______________

solenoid.

Electrical power is expressed in _____________

watts.

Flexible metal braids called ____________ straps connect the control surfaces to the aircraft structure to prevent the buildup of static charges.

bonding

One _____________ is equal to a magnetic flux density of one weber per meter squared.

tesla

The unit of electrical pressure is known as the ____________

volt.

According to the wire chart illustrated in figure 3-34 on page 3-17, a six-gauge MIL-W-7072 aluminum wire will carry ________ amps in free air, and a six-gauge MIL-W-5086 copper wire will carry ________ amps in free air. The reason for the difference is that copper has __________ resistance than the aluminum.

83, 101, less

How much current is required for a 12-volt DC electric motor to produce 1/4 horsepower if we assume that there are no losses in the system? 1/4 horsepower = _________ watts In a 12-volt motor this will require _________ amps.

186.5 15.54

When a five-ohm resistance is placed in a 20-volt circuit, how much current will flow?

4 amps

If three amps of current are flowing in a 12-vol circuit, how much resistance is present?

4 Ω

The speed of electron movement is considered to be ______________ miles per second. This is the same as the speed of _____________

186,000, light

How much power is needed to lift a 12,000-pound aircraft three feet in one minute? __________ horsepower __________ watts

1.09 813.82