Aircraft Electricity 1

Pataasin ang iyong marka sa homework at exams ngayon gamit ang Quizwiz!

What device is designed to open and disconnect a circuit in the event of excessive current?

fuse

Direct current is decreased as ___________.

Uni-directional

The amount of potential necessary to cause one coulomb to produce one joule of work is a(n) __________.

Volt

What force pushes the electrons through a resistance in a circuit?

Voltage

What is another term for electromotive force (EMF)?

Voltage - Pressure

Resistors functioning as _________________ are used in applications involving field-effect transistors (FETs) and multi-range voltmeter circuits.

Voltage dividers

What unit is used to express electrical power?

Watt

The amount of electrical power being used in a circuit is measured in __________.

Watts

If a circuit is open, current ___________________ flow.

Will not

A voltage that is positive with respect to ground is a(n) ____________________________________ voltage.

above ground

In parallel circuits, the voltage drop across any branch is the same as the _________________.

applied voltage

A basic law of magnetism states that unlike poles ___________ and like poles _____________.

attract, repel

If a permanent magnet is cut into pieces, each piece __________ a separate magnet.

becomes

Altering current is described as ___________.

bi-directional

A combination circuit is a circuit that contains ____________________.

both series and parallel components.

A complete circuit is often referred to as a(n) _______________ circuit.

closed

The angular difference between true north and magnetic north is known as the angle of ______________.

declination

Magnetism can be explained in terms of _______________ spin patterns.

electron

Insulators are the only materials that can hold __________ stationary

electrons.

In the English system of measure, magnetic strength is measured in terms of _____________________.

flux density.

Magnetic lines of force are referred to as ________________.

flux lines

The neutral conductor is also referred to as the ________ conductor.

grounded

A series circuit _________________ path(s) for current flow.

has one

Electrostatic charges occur on _____________.

insulators

To locate the north pole of an electromagnet, use the ________ -hand rule.

left

Man-made permanent magnets retain their magnetism _____ than natural magnets.

longer

Lodestone is a name for a naturally occurring magnetic material that is also called ________________.

magnetite

What type of fixed resistor is made by applying a film of metal to a ceramic rod in a vacuum?

metal film

What type of fixed resistor is made by combining metal with glass and then applying it to a ceramic base as a thick film?

metal glaze

What type of resistor operates by moving the wiper arm with a screw of some number of turns?

multi-turn variable resistor

If a thundercloud has a positive charge, the current in the lightning bolt will flow from the ____________________.

negative

Within a lightning bolt, current flows _____________________________________.

negative to positive.

A junction point of current paths is often called a _____________.

node

The shock that results from walking across a carpet and touching a doorknob is an example of a(n) _________________ static charge.

nuisance

The current, voltage, power, and resistance in a series circuit can be calculated using ______________ law.

ohms

Circuits that have more than one path for current flow are _____ circuits.

parallel

By observing the direction of current flow through the circuit, voltage ____________________ can be determined.

polarity

What is another term for a variable resistor?

potentiometer

Solving combination circuits includes a step in which you ___________________________________________________________________.

reduce the circuit to a simple circuit.

A variable resistor with two terminals is called a ______________.

rheostat

When a magnetic material's molecules are all lined up, and increases in current flow no longer cause increases in magnetic field strength, the material has reached __________________.

saturation

There is very little resistance and a large amount of current flows in a(n) _________________ circuit.

short

In a parallel circuit, the total current flow is equal to the _________ of the currents through all the branches.

sum

The static charge sometimes used during spray painting is called a _____ static charge.

useful

A resistor whose values can be varied over a range of values is called a ______________ resistor.

variable

Which is correct concerning a parallel circuit?

Total resistance will be smaller than the smallest resistor.

What type of fixed resistor is made by applying a film of carbon to a ceramic rod?

carbon film

A point that is used as a common connection for other parts of a circuit not actually driven into the ground is called a _____________ ground.

chassis

The regions formed in the molecular structure of magnetic metals are sometimes called magnetic _____________.

domains

In the English system, the total force producing a magnetic field is the _______________________.

magnetomotive force

In a clothes dryer, the greatest static charges generally are built up on ________________ fabrics.

man-made

When an object protected by a lightning ___________ is struck by a lightning bolt, it will bleed the lightning discharge to ground before the protected object can be harmed.

rod

Selenium is a(n) ________________.

semi-conductor

A circuit that has only one path for current flow is a ______________ circuit

series

Combination circuits are circuits that contain both series and parallel branches.

true

The values of a resistor can often be determined by the "color code."

true

A conductor is made from a material that contains between _________ valence electrons.

1 and 3

An electrical circuit has a voltage of 50V and a resistance of 5Ω. What is the value of current?

10A (I=E/R)

An electric circuit has a resistance of 20Ω. The current is measured to be 6A. How many volts are applied to the circuit?

120V (E=I*R)

A toaster is listed as 1560 W. When it is plugged into a 120V circuit and starts to make toast, how many amperes will it draw?

13A (I=P/E)

A three-branch parallel circuit has a total resistance of 385.83Ω. Two of the resistors are 680Ω and 1500Ω. What is the value of the third resistor?

2200Ω

A 24V source is required to furnish 48W to a parallel circuit consisting of four resistors of equal value. What is the voltage drop across each resistor.

24V - stays the same

The Greeks were the first to discover electricity about _________ years ago.

2500

A parallel circuit is composed of two 60Ω resistors. What is the total resistance?

30Ω (Rt=1/((1/R1)+(1/R2)))

A semiconductor contains ________ valence electrons.

4

Approximately how many horsepower is an electrical device listed as 3000 watts?

4.02HP (745.7w to 1hp)

An electrical motor is running on 120V. The current is measured to be 2A. How many Ohm's of resistance is the motor?

60Ω (R=E/I)

A parallel circuit composed of a 10Ω and a 22Ω resistor has a voltage of 60V. What is the current in the 10Ω resistor?

6A (I=E/R)

What is the maximum number of valence electrons in an atom?

8

A three-branch parallel circuit has resistors of 27Ω, 56Ω, and 15Ω. What is the total resistance?

8.23Ω (Rt=1/((1/R1)+(1/R2)))

What is the applied voltage in a series circuit with two resistors (25V and 60V, respectively)?

85V (Voltage applied to a series circuit is equal to the sum of the individual voltage drops.)

A method for finding total resistance of parallel resistors is ___________.

A. product / sum B. reciprocal formula C. resistors of equal value D. All of the above D

What type of current reverses its direction of flow at regular intervals?

AC - Alternating current

A precipitator is a type of ____________________.

Air Filter

One coulomb per second is equal to one _________.

Ampere.

What force is demonstrated in objects with unlike charges?

Attraction

What type of current flows in only one direction?

DC - Direct Current

To symbolize a ground point made by physically driving an object such as a rod or pipe into the ground, a(n) _________________ ground symbol is used.

Earth

What type of magnet depends on flowing current to produce a magnetic field?

Electromagnet

Electrical current is the flow of ___________.

Electrons

Which of the following formulas is the general voltage divider formula?

Ex= (Rx/Rt)*Et

A thundercloud contains only positive electric charges.

False

Current always flows from positive to negative.

False

During normal operation of a typical 120-volt appliance circuit, current flows through the hot, grounding, and neutral conductors.

False

In electrical schematics, the symbol used to represent a resistor is standard.

False

Voltage flows through an electric circuit like water flows through a pipe.

False

What type of resistors can only have ohmic value?

Fixed

What standard prefic in engineering notation indicates multiplication by 1,000,000,000?

Giga

What color used as the multiplier band means to divide the combined first two numbers by 10?

Gold

Static electricity refers to electrons that ________________moving.

Are not

What type of fixed resistor is made from a compound of carbon graphite and resin bonding material?

Composition carbon

What part of an atom has a negative charge?

Electron

The three substances that form natural magnets are ______,________, and ______.

Iron, nickel, cobalt

What is the most common method of producing electricity?

Magnatism

The precipitator uses a high-voltage DC power supply to provide a set of wires with a positive charge and a set of plates with a ________ charge.

Negative

The unit of resistance to current flow is the _________.

Ohm

The statement, "In a DC circuit, the current is directly proportional to the voltage and inversely proportional to resistance," is known as _________ law.

Ohm's

The valence shell of an atom is the ________ shell.

Outer

What part of an atom has a positive charge?

Proton

What are the three principle parts of an atom?

Proton, neutron, electron

The atomic number of an element is the number of ____________ in the nucleus.

Protons

The nucleus of an atom contains ____________________.

Protons and Neutrons

A basic law of physics states that like charges _______ and opposite charges _______.

Repel, Attract

What force is demonstrated in objects with like charges?

Repulsion

What causes a wire to become warm when current flows through it?

Resistance

The semi-conductor material used as a coating on copy machine drums is ______________.

Selenium

What part of an atom has no charge?

Neutron

An electroscope can be used to determine the polarity of an electrostatic charge.

True

Copy machines operate on the principle of static electricity.

True

Lightning is the result of static charge built up in the clouds that contain a large amount of moisture.

True

Lightning rods provide an easy path to ground for current.

True

The velocity of AC through a conductor is ____________ the speed of light.

less than

The measure of a material's ability to be magnetized is called _______________.

permeability

A parallel circuit composed of a 150Ω and a 270Ω resistor has a voltage of 120V. What is the current in the 150Ω resistor?

.8A (I=E/R)

A series circuit has a total resistance of 180Ω and an applied voltage of 120V. What is the current flow?

.667A (I=E/R)

A three-resistor circuit has a total power of 25W. Two of the resistors dissipate 10W and 5W, respectively. How much power does the third resistor dissipate?

10W

A two-branch parallel has a 30Ω and a 15Ω resistor. What is the total resistance?

10Ω (Rt=1/((1/R1)+(1/R2)))

A two-resistor series circuit has an applied voltage of 100V. The voltage across one of the resistors is 40V. What is the voltage across the other resistor?

60V (Voltage applied to a series circuit is equal to the sum of the individual voltage drops.)

An insulator is a material containing ____________ valence electrons.

7 and 8

A series circuit has a total resistance of 240Ω and a current flow of 4A. What is the applied voltage?

960V (E=I*R)

What is the smallest part of an element that still retains the properties of that element?

Atom

Imagine a water system with a holding tank, pump, and return lines. What would happen to the resistance to flow if a return path is added to the system.

Lessens

The north magnetic pole of a compass needle is attracted to the ________________ magnetic pole of the earth.

South

An increase in ___________, not resistance, results in an increase of load.

current

In series circuits, the _____________ is the same at any point in the circuit.

current

The term: "load" refers to the amount of ____________ in a circuit branch.

current

When a circuit has only one path, the ______________ is the same at any point.

current

Parallel circuits are also referred to as ______________.

current dividers

A voltage ________ is used to provide different voltages between certain points in a circuit.

divider

In a series circuit, the sum of the voltage drop is ______________ the applied voltage.

equal

One of the rules for parallel circuits states that the voltage is different across each branch of the circuit.

false.

In a parallel circuit, the total resistance is _______________________________ value resistor.

less than the

Bringing a charged test object near the ball of a charged electroscope causes the leaves to move closer together. This indicates that the test object charge is the ______________ polarity as the electroscope charge.

opposite

A variable resistor with three terminals is called a ______________.

potentiometer

The ______________ of a resistor indicates the plus and minus limits of a resistors ohmic value.

tolerance

What is indicated by the fourth color band on a resistor?

tolerance

In a combination circuit, to identify series and parallel elements, you should ________________________.

trace the current path.

The 3 rules for parallel circuits are as follows: 1. The voltage drop across any branch of a parallel circuit is the same as the applied voltage. 2. The total current is the sum of the individual currents through each path in the circuit(current adds) 3. The total resistance is the reciprocal of the sum of the reciprocals of the branch resistances.

true

The 3 rules for series circuits are as follows: 1. The current is the same at any point in the circuit. 2. The total resistance is the sum of the individual resistances. 3. The applied voltage is equal to the sum of the voltage drops across all resistors.

true

Earth contains magnetic poles.

True

The grounding prong of a plug should never be cut off or bypassed.

True

Matter can exist in only two states: solid or liquid.

False

Most lightning discharges associated with a cloud occur between the cloud and the ground.

False

The north pole of a compass needle points in the direction of the south geographic pole.

False

There are many more resistance values available for ten percent tolerance resistors than for one percent tolerance resistors.

False

A grounding conductor helps prevent a shock hazard in the event that an ungrounded, or hot, conductor comes in contact with the case or frame of an appliance.

True

The strength of an electromagnet is primarily proportional to its ___________________________.

ampere turns

A lightning protection device that is grounded at one end, with the other end close to but not touching the object to be protected, is called a lightning ____________.

arrester

The measure of a materials resistance in magnetism is known as ____________________.

reluctance.

A series circuit has two resistors that dissipate 10W and 15W, respectively. What is the total power dissipation of the circuit?

25W

How many color bands are used on resistors that have a tolerance of +-20%?

3

What type of circuit generally occurs when the conductors leading from and back to the power source become connected?

Short circuit

Matter has mass and occupies space

True

What law states that the force of electrostatic attraction or repulsion is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them?

Coulombs law

If an object is placed in the field of a strong electromagnet connected to an AC line, the object will be _________________________.

De-magnetized

What type of magnets do not require any power of force to maintain their field?

Permanent

The amount of current flowing through each resistor is directly proportional to its resistance.

true

When solving combination circuits, it is generally easier if the circuit is reduced to simpler circuits.

true

The amount of ___ across a resistor is proportional to its resistance.

voltage drop

What type of fixed resistor is made by winding a piece of resistive wire around a ceramic core?

wire wound

What type of resistors are generally used when a high power rating is needed?

wire wound


Kaugnay na mga set ng pag-aaral

Chapter 19: The Elbow, Forearm, Wrist and Hand

View Set

Emirates Airlines | Speech Training | Lesson 1

View Set

4.2-4.3 Glycolysis and Fermentation/ Aerobic Respiration

View Set

Leadership and Management - U World

View Set

KINESIOLOGY FINGER & HAND JOINTS (EXTRINSIC AND INTRINSIC)

View Set

Phlebotomy chapter 8 (certification exam prep)

View Set

Chapter 2 Beginnings of English America/ Inquizitive

View Set

Milady Advanced Esthetics Chapter 3: Histology of the Cell & Skin

View Set