Atp106, week 1-4

Name 2 factors that determine the speed an electron attains inside a gas environment.

Applied Voltage, Distance Traveled

Alternating current is described as ________

BIDIRECTIONAL

Why do Static Charges accumulate On Insulator materials only?

Because Insulators hold the electrons in position.

Why is Static electricity considered to be a charge and not a Current?

Because the electrons are sitting still and not- moving

What device is used for lightning protection?

Both A and B. A= Lightning Rods, B= Lightening Arrestors

What is the negative terminal of a power source called?

Cathode

What is the 277-volt-single-phase-60-hertz system used for?

LIGHTING BRANCH CIRCUITS

What part of an atom has a positive charge?

proton

What is the positive terminal of a power source Called?

Anode

What Is an atom which has lost One or more electrons called?

Positive

Refer to the circuit shown in Figure 14-21. Assume that the inductor has a wire resistance of 0.2 Ω and the resistor has a value of 250 Ω. If a current of 3 A is flowing through the inductor, what will be the maximum induced voltage when the switch is opened?

-750.6 V

What is a secondary cell?

. A CELL WHICH CAN BE RECHARGED

What is the advantage of the Alkaline Cell as compared with the Carbon-Zinc Cell?

. LONGER LIFE

The effective voltage of alternating current is __________ times its highest or peak voltage.

.707

An inductor has an inductance of 0.025 H and a wire resistance of 3 Ω. How long will it take the current to reach its full Ohm's law value?

0.0417 S

What is the Voltage produced by a Silicon Solar Cell?

0.5 V

How many lines of magnetic flux must be cut in 1 s to induce a voltage of 1 V?

100,000,000

What is the voltage of a system with a wye transformer hookup?

208 VOLTS/THREE PHASE/60 HERTZ

What type of electrical system is most commonly used when structures primarily require a high number of 115-volt circuits available for use in the structure. such as hospitals, schools, motels, and office buildings?

208 VOLTS/THREE PHASE/60 HERTZ

Name the four voltage-current characteristics commonly used today.

208 VOLTS/THREE PHASE/60 HERTZ 480 VOLTS/THREE PHASE/60 HERTZ 230 VOLTS/THREE PHASE/60 HERTZ 230-VOLTS/SINGLE PHASE/60 HERTZ

What is the voltage of a system with a delta transformer hookup?

230 VOLTS/THREE PHASE/60 HERTZ

What is the common electrical service to a residence?

240 V/1Ø/60 HZ

A force of 1 ounce is equal to how many dynes?

27,800

Three 12-V, 100 Amp hour batteries are connected in series. What is the output Voltage and Amp hour capacity of this connection?

36 VOLTS, 100 AMP HOURS

Into how many time constants is an exponential curve divided?

5

A 6-v Lead - acid battery has and Amp hour rating of 180 AmP hours. The battery is to be load tested. What should be the test current and what are the maximum permissible amount and duration of the Voltage drop.

540 Amps, 4.8 VOltS

What is the common frequency of alternating current in the United States?

60 HERTZ

Each time constant of an exponential curve is equal to what percentage of the maximum amount of charge?

63.2%

A solar cell can produce a voltage of 0.5 V and has a current capacity of 0.1 A. What voltage and amperage would be generated by the following configuration? Three banks of 12 cells connected in series. Each bank should then be connected in parallel.

6v , 0.3A

What is a primary cell?

A CELL WHICH CANNOT BE RECHARGED

What is a voltaic cell?

A DEVICE WHICH CONVERTS CHEMICAL ENERGY INTO ELECTRICAL ENERGY

What is an electroscope?

A device used to test the electrostatic charge of a material

Name the four voltage-current characteristics commonly used today.

A. 208 VOLTS/THREE PHASE/60 HERTZ B. 480 VOLTS/THREE PHASE/60 HERTZ F. 230 VOLTS/THREE PHASE/60 HERTZ G. 230-VOLTS/SINGLE PHASE/60 HERTZ

What is a group of cells connected together called?

A. A BATTERY B. A VOLTAIC PILE C. NEITHER A NOR B D. BOTH A & B (correct answer)

Alternating current is __________.

A. AN ALTERNATING FLOW OF ELECTRONS B. ELECTRONS REVERSING THEIR FLOW AT REGULAR INTERVALS C. THE MOST COMMONLY USED CURRENT D. ALL OF THE ABOVE Answer is D (all the above)

Alternating current is __________.

A. AN ALTERNATING FLOW OF ELECTRONS B. ELECTRONS REVERSING THEIR FLOW AT REGULAR INTERVALS C. THE MOST COMMONLY USED CURRENT D. ALL OF THE ABOVE (answer is D all the above)

What is used as the Electrolyte in a Carbon-Zinc cell?

AMMONIUM CHLORIDE, MANGANESE DIOXIDE AND GRANULATED CARBON

The amount of current the battery can produce for a period of 20 hours at 80 degrees Fahrenheit is known as what?

Amp Hours

What is the difference between single-phase and three-phase alternating current?

D. SINGLE-PHASE ALTERNATING CURRENT HAS TWO POWER LEGS WHILE THREE-PHASE ALTERNATING CURRENT HAS THREE POWER LEGS

What electronic component is often used to prevent large voltage spikes from being produced when the current flow through an inductor is suddenly terminated?

Diode

Direct current is used in which of the following applications in the industry?

ELECTRONIC CONTROL COMPONENTS

What is the process of electronically separating elements electronically?

Electrolysis

What kind of liquid solution permits the flow of electric current?

Electrolyte

What is the most important factor in the ionization of a gas?

Electron Impact

What are the three principle parts of an atom ?

Electron, Neutron and proton

Electrical current is the flow of _________

Electrons

Match term to definition.

F1ux density - measurement of the strength of a magnetic Coercive Force - a measurement of a materials ability to retain magnetism Saturation - the point at which a further increase in magnetizing current causes a minimal increase ln the magnetic field strength of an electromagnet. Residual magnetism - The amount of magnetic force remaining In a piece of material after the magnetizing force has been removed. Permeability- The measure of a material willingness to become magnetized. Reluctance - resistance to magnetism

True or False? Single-phase alternating current is common in most commercial and industrial structures.

FALSE

A Thundercloud has a negative charge, and an object on the ground has a positive charge. Which way will the lightning discharge?

From the cloud to the ground

What is the sum of the resistance and reactance in an alternating current circuit?

IMPEDANCE

.What materials are used in the construction of a Type J thermocouple?

IRON AND CONSTANTAN

What is the effect on induced voltage of adding more turns of wire to a coil?

IT ADDS TOGETHER

The amount of voltage required to start conduction in a gas is called what?

Ionization potential

Conduction in a liquid depends on the movement of what?

Ions

What special property does this material have that makes it useful in a copy machine ?

It's conductivity changes with a change in light intensity

What were early natural magnets know so as ?

Lodestones

What material is used as the positive electrode in an Alkaline Cell?

MANGANESE DIOXIDE

What material is used as the positive electrode in a Zinc-Mercury cell?

MERCURIC OXIDE

What is an atom which has gained One or more electrons

Negative

What part of a atom has no charge?

Neutron

Which of the following is not one of the three basic substances that can be used to produce ionization In a liquid?

Oxygen

The number of currents alternating at different time intervals in an alternating current circuit are called what?

PHASES

What is the voltage range in which alternating current equipment can be operated?

PLUS OR MINUS 10 PERCENT

What does the word piezo mean?

PRESSURE

An electroscope has been charged with a negative charge. An object with an unknown charge is brought close to the electroscope. The leaves of the electroscope come closer together. Does the object have a positive or a negative charge?

Positive charge

What determines the density of the molecules in a gas environment?

Pressure

What is the resistance to the changing flow of alternating current?

REACTANCE

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

Repel ; Attract

What happens if the South Pole of one magnet is brought close to the South Pole of another magnet?

Repel each other

Identify the characteristics of AC and DC voltage.

Runs at a higher temperature DC Easy to produce AC More dangerous to transfer DC Easier to transform voltages AC Cheaper to produce AC Voltage remains at a constant value DC

What is the difference between single-phase and three-phase alternating current?

SINGLE-PHASE ALTERNATING CURRENT HAS TWO POWER LEGS WHILE THREE-PHASE ALTERNATING CURRENT HAS THREE POWER LEGS

What type of material is used to coat the aluminum drum of a copy machine?

Selenium

An insulator is a material containing_________ Valence electrons.

Seven or Eight

Is the north magnetic pole of the earth a north polarity or a south polarity?

South Polarity

What determines the strength of the magnetic field when current flows through a conductor?

THE AMOUNT OF CURRENT FLOW

Which of the following is not a factor that determines the amount of induced voltage in a coil?

THE AMOUNT OF CURRENT FLOW

A magnetic field is _______.

THE AREA IN WHICH A MAGNETIC FORCE OPERATES

What determines the polarity of magnetism when current flows through a conductor?

THE DIRECTION OF CURRENT FLOW

What factors determine the amount of voltage produced by a cell?

THE MATERIALS

What does not determine the amount of voltage produced by a thermocouple?

THE SIZE OF THE THERMOCOUPLE

What determines the current capacity of a Solar Cell?

THE SURFACE AREA OF THE CELL

True or False? Inductance in an AC circuit is an effect that is due to the magnetic fields caused by the current flow.

TRUE

What determines the amount of current a cell can provide?

The Size

What determines the thickness of the coating during an electroplating process?

The length of time

What determines the color of light emitted by a gas filled tube?

The type of gas

What Is used to hold a sulfate ion together?

Two extra electrons

A thermocouple is to be used to measure a temperature of 2800°F. Which thermocouples are not used to measure this temperature?

Type J

Direct current is described as________

Unidirectional

How can the polarity of an electromagnet be determined if the direction of current flow is known ?

Using the Left- Hand Rule

Can one thundercloud contain both positive and negative charges ?

Yes

What part of an atom has a negative charge?

electron

What are the advantages and disadvantages of using the following types of motors?

shaded-pole motor Advantage: stalls without damage; Disadvantage: low starting torque Capacitor start - copacitor run motor Advantage: good starting torque; Disadvantage: cost PSC motor Advantage: good running efficiency;Disadvantage: difficult to reverse split-phase motor Advantage: cost; Disadvantage: moderate starting torque