Electroticity Chapter 12 & 13 (Mid-Term)

If a parallel circuit has three loads of equal resistance and a voltage of 120V is applied to the circuit, what will the voltage drop be across each load?

120V

Inductive reactance affects the true power of a circuit because it cause____

Current to lag behind voltage

When a conductor wound around a piece of soft iron conducts current and turns the soft iron into magnet, this phenomenon is called_____

Electromagnetism

Which of the following atomic particles is not found in the nucleus of an atom? Electron, Neutron, or Proton

Electron

If the true power and apparent power are not equal, the power factor of a circuit is____

Less than %100

A circuit fundamental that has a full shaded circle at the bottom of the stem along with an attached shaded circle on the left side of the line that is connected to the stem along with an attached shaded circle that is attached under the far right side of the line.

Liquid Level Switch

electromagnetism inductiony

Magensric Effect caused by current flowing through a conductor

The amount of Energy used to generate a magnetic field is called what?

Magnetomotive Force

Which of the following values is always calculated in volt-amperes?

Apparent Power

Which of the following substances in a semiconductor? Copper, Silicon, Mica, Aluminum

Mica

Induction

Process of transferring electricity using a magnetic field

Wire terminal that wears a round head with a complete circle in the middle.

Ring

An a/c generator uses a ___to transmit current to the wire loop

Slip Ring

A semiconductor may be triggered to function as conductor

Temperature, Light Intensity, Electrical Signal

A circuit fundamental that has a half open box that is on the right side of the stem along with a full shaded circle that is attract to the left end of the line and a detached circle that is under the right side side of the stem. The circle is nearest to the box that is shaded. You know this....

Temperature-Activated Switch

The most widely used polyphase power arrangement used in HVACR is _____power

Three Phase

An a/c motor speed is determined by the number of turns in the stator winding, the applied age & frequency

True

Bonding creates a good metallic connection through an electrical system, which diverts current, in the case of a fault, through the metallic connection and back to earth.

True

Copper and iron are both electrical conductor

True

Electrical Devices(loads) are arranged in the circuit so that each is connected to both supply voltage conductors

True

In an electrical circuit, inductive components can cause voltage and current to be out of phase

True

The actual power used by a circuit is the _____power of a circuit

True

The current in a series is shown by the following equation I(t)= I(1)= I(2) = I(3) = I(4)......

True

The main types of over current protection devices are the circuit breaker, fuse, thermistor, and gfci

True

The reactance of a series is shown by the following equation: R(t)= R(1) + R(2) + R(3) + R(4) + ......

True

The sum of the voltage drop is shown by the equation E(t)= E(1) + E(2) + E(3) + E(4).....

True

Typical a/c motors take a standard 60Hz incoming signal

Truev

The effective voltage of an alternating current is calculated using the formula____

V(Max) x .707)

In a series circuit, the load with the lowest resistance has the highest___

Voltage Drop

Which electrical problem involves a circuit's applied voltage bring reduced along a conductor to a level that is too low for safe use on the electrical load

Voltage Drop

Electrical Problem in circuits are commonly the results of one of following five problems: short circuit, a ground fault , an overload, an unintentional voltage drop

short circuit, a ground fault , an overload, an unintentional voltage drop

Electrical generators produce voltage by moving a conductoer____

Across a magnetic field

A form of circuit protection that employs a solenoid to open the circuit if current exceeds a predetermined level is a ___________.

Circuit Breaker

A conductor is a substance with no free electrons in its structure

False

A GFCI opens when as little as ____ amperes peaks out of a circuit and into the grounding system

.006

To calculate an alternating currents root mean square, multiply the maximum voltage value by_____

.707

Electricity Distributed in North America has a frequency of __

60 hz

Joining all the metallic components of an electrical system, even those that do not normally carry current, is defined as ___________.

Bonding

Direct Current

Current that flows in only one direction

alternating current

Current that switches its direction if at regular.

Regarding magnetism, like poles do what?

They cause one of the poles to reverse in orientation

The voltage , current, and power of an alternating current are constantly changing within a cycle. Root mean squares(rms) values are used to calculate the equivalent dc values of an ac sine wave

True

The voltage drop of an electrical load is equal to the current passing through the load multiplied by the resistance of the load.

True

The wiring of a house is an example of a parallel circuit

True

Total resistance of a parallel circuit cannot be obtained by taking the sum of all resistances. It is calculated by the following if two resistance are used: R(t)= R1xR2 divides by R1+R2

True

When multiplying decimals u add the produc

True

VFD

Variable Frequency Drives

An ungrounded conductor is also sometimes called a ____

Hot Wire

A circuit fundamental that has two spaced parallel lines that attached to to the left side of the unshaded circle

Motor

Grounding and bonding all electrical, and metallic components help to prevent electrical stock.

True

I'm a circuit with a constant voltage, the current and resistance are inversely related.

True

If more coil turns are added to the winding of an electromagnet, the strength of the electromagnet's magnetic field will increase.

True

Iron has higher resistance than copper

True

The power source that supplies power to a Class 2 circuit cannot have an output greater than____

30V and 1000VA

The electrical property that opposes a change in current is called _____

Inductance

How many watts does an electrical loud use if a current of 1 A flows through it when the load is connected to a 1V power source?

1 watt

How long does alternate current flow in one direction when a frequency of 60Hz is used?

1/120 if a second

What is the power used by an electric motor that draws a current of 15A from 240V power source?

3600

closed circuit

A circuit with a complete path, allowing electrons to flow

open circuit

A circuit with an electrical switch or device that is disconnected

A transformer can only operate using___

Alternating Current

Electrical wire size is specified by the ____

American Wire Gage

CSCR

Capacitor-Start, Capacitors Run Motor

A circuit fundamental that is represented by Two sideway t's that do not connect

Capacitors

A dc generator uses a____to transmit current from the wire loop

Commutator

One current of one ampere is equal to the flow of one _____Per Second

Coulomb

If an electric circuit is purely resistive, it's apparent power cannot equal it's true power

False

If the current to an electromagnet is turned off, the magnetic field becomes only slightly weaker

False

The closer together a number of windings are in an electromagnet, the weaker the magnetic field will be.

False

The digit 4 has a value greater than the digit 7.

False

Voltage across any load in any load in a series circuit is equal.

False

A circuit fundamental that has a right facing triangle at the bottom, a shaded ball that connected on the left end of the line that Is connected to the stem. It also had a detached shaded ball on the right side of the line that is gonneced the stem

Flow-Activated Switch

A form of circuit protection that contains a metal conductor that melts to open a circuit when current is too high is a ____________.

Fuse

A circuit fundamental that looks like an a/c current

Fusible Link

The ground wire in an HVCR Electrical circuit is always

Green

A circuit fundamental that has a flipped t along with the other spaced lines behind it.

Ground Connection

A form of circuit protection that opens the circuit if it detects an imbalance between the ungrounded and grounded wires of a circuit is a ____________.

Ground Fault Circuit Interrupter

When voltage and current reach their positive and negative peaks at the same time in an alternating current cycle, they are said to be____

In phase

If the voltage in a circuit is constant, the current in the circuit _____where the resistance is decreased.

Increase

When a material becomes a magnet because it is placed in a magnetic field, this phenomenon is called_____

Induced magnetism

Dielectric

Insulating material used to separate metal surfaces in a capacitor

Line voltage

Is the voltage supplied to the equipment from the main power source of a structure and typically has a value of 115-120 Volts or 240

When current flows through an electric component due to a potential difference, electrical ____power

Power

The ratio of true power to opponent power is____

Power Factor

A circuit fundamental that has half of a circle at the bottom of the stem along with a full shaded circle attached at the end of the line that is attract to the stem and a detached circle above the right end of the line that is connected to the stem.

Pressure Activated Switch

In transformer operation, a magnetic field is initially generated by the current in the_____

Secondary Coil

A low-torque, single-phase motor that uses shaded field poles, instead of a start winding, to produce start torque. It's construction is different than PSC & Sit phase motors.

Shaded-Pole Motor

Which electrical problem involves extremely high current going around an electric load?

Short Circuit

A form of circuit protection that only regulates current flow by changing its resistance based on heat is a _____

Thermistor

An overcurrent protection device that regulates current by changing it's resistance based on hear is ____

Thermistor

I(Amps)= E(Voltage) divider by R( Resistance)

This formula is used to calculate the current flowing through a circuit

I'm a three phase voltage cycle, three separate voltage signals are delayed so they peak at different _____

Times

A control circuit is an electric circuit that controls some major load in the system

True

A positive number is a number that has a value of greater than zero

True

A step down transformer has more turns in its primary coil than in its secondary coil

True

A three phase motor is an inductions motor that has three sets of stator windings energized by a three phase power signal. In many cases each set has two windings. Each set of windings is connected to one phase of the three phase power source

True

Electrical loads need to be compatible with the power supplied by the electrical utility company. Important variables to match include____

Voltage Phase Current Capacity Voltage Level Frequency

Since resistance limits the flow of current it causes a ____

Voltage drop

Capacitive Reactance affects true power of a circuit because it causes____

Voltage to lag behind current