Hvac unit 5 introduction to electricity
1 watt is equal to blank
3.41 BTUs
What is 1 watt equivalent to
3.41 BTUs 3413 kilowatts
1 kilowatt equals blank BTUs
3.412 btu
A circuit has 120 volts 30 ohms what is I
4 amps
What is 1 amp equivalent to
1000 milliamps 1 million microamps
What is 1 voltage equivalent to
1000 millivolts 1 million microvolts
What is 1 kilohm equivalent to
1000 ohms
What is 1 kilovolt equal to
1000 volt
A resistance of 200 Holmes and 50 amps produces how many volts
10000
More people have been killed by contact with
120 volt AC
The nominal supply voltage of a safety control circuit shall not exceed blank volts
120 volts
At what volt has the majority of fatalities.
120 volts ac as little as 42 volts DC can be lethal.
How many inches of wire should be left for making joints or for the connection to receptacles
6 inches should be left at each outlet for making joint or for the connection to receptacles
What is electromagnetic induction
If a conductor is moved across the magnetic field as indicated voltage is generated in that conductor
Define electromagnetic induction
If a conductor is moved across the magnetic field as indicated voltage is generated in that conductor.
Define thermal electricity
If heat is applied to two different metals joined together
In a series circuit can there be more than one path for the current to flow
In a series circuit there is only 1 path of current to flow.
When using a meter to measure voltage how mustuch the voltmeter be connected into the circuit
In parallel to the circuit
When using a amp meter to measure current how much the ammeter be connected into the circuit
In series with the circuit
Name all electrical sources which must be made in operable and what is this state called.
Including electrical pneumatic hydraulic gravitational must be made inoperable this is often called zero mechanical state
Black wire sometimes red or blue
Insulated live or hot conductors
Generally electricity arrives at a receptacle inside a two conductor cable and includes a ground wire. Generally what are the white and natural gray
Insulated neutral conductors
What is a VOM or multimeter used for
Its functions as a voltmeter an amp meter and an ohmmeter
What's the purpose of a running capacitor
Keeps voltage source constant
What is the fundamental law that governs the way charged particles behave
Like charges repel unlike charges attract
How is thermal electricity measured
Measure millivolts DC
how is thermal electricity measured
Millivolts
Electrons charge is considered to be blank charge
Negative
In which direction in a conductor does DC always flow
Negative to positive
Atoms are made up of three parts what are they
Neutrons protons and electrons
Can you take a victim who is still connected to the electric power
Never touch a victim who is still connected to the electric power.
What type of meter is used to measure resistance or continuity
Ohmmeter
What is 1000 amp equal to or equivalent to
One kilo ampere
Which letter represents power and how is it measured
P measured in watts
In most jurisdictions blank are required for all electrical work to be performed
Permits
Pressure is applied to certain crystal materials what is this called
Piezoelectricity such as gas barbecues
Define power and work
Power is the rate at which work is done
In the absence of other instructions what five steps must be followed to rescue a shock victim
Protect yourself.Dp do not touch the energies victim .Free the victim from electrical contact Apply CPR. Call 911 Continue CPR until a medical authority tells you to stop
What happens to resistance when the skin is wet or salty
Resistance drops
When skin is wet or salty it blank blank to several hundred from several thousand ohms
Resistance drops
How does the step down transformer differ from the single phase transformer operation
Secondary winding has fewer turns than the primary winding so the secondary voltage is less than the primary voltage also the secondary current is greater than the primary current windings primary and secondary will be proportionate. Check answer.
The strength of the forces of attraction and repulsion depends on A the amount of charge on each subject B the square of the distance between the object or C both of the above
See both of the above
What is the definition of Ohm's law
The current flowing in electrical circuit is directly proportional to the applied voltage
In a parallel circuit what voltage is applied across each branch
The entire sourceStudying Hvac unit 5 introduction to electricity on Quizlet: https://quizlet.com/105226579/hvac-unit-5-introduction-to-electricity-flash-cards/ voltage applied voltage
What is formed when several thermocouples are joined together
Thermopile
What are the laws of a parallel circuit
Voltage is constant across each branch in the circuit ET=E1=E2 check answer amperage is the sum of the current flowing through each branch. Resistance RT is smaller than the smallest resistor in the circuit.
Electric current
When electrons are made to move in the same direction they produce an electric current.p
Describe photo electricity
When light strikes certain materials such as potassium and sodium the energy from the light causes the Adam to release electrons this is called the photoelectric effect UV an infrared
What is the definition of electromagnetism
Whenever current flows in a conductor a magnetic field forms around the conductor also if a conductor is moved within a magnetic field of voltage will be induced and current will flow in the conductor
The flow of electric current carries energy that can perform blank
Work
are the terminals on receptacles usually identified to indicate which conductor is to be connected for example the neutral wire terminal is identified by a metallic coding or is made of metal that is substantially white silver in color or is Mark W or white adjacent to the terminal the ground terminal screwing head nut or clamp is colored green
Yes
Does the load usually have resistance in the electrical circuit
Yes the load usually has resistance.
True or false all electric power for the heating unit and associated equipment operating in connection with it shall be obtained from a double branch circuit that shall be used for other purposes
False
Name three circuit protective devices
Fuses circuit breakers thermal and magnetic overloads
Green
Green wire only for ground conductors
What type of charge is associated with the following. Fewer electrons than protons fewer protons than electron and the same amount.lectrns and protons.
Has a positive charge has a negative charge is neutral
When electricity flows in a current it can produce these useful effects name three
Heat magnetism chemical changes
Applying enough force to remove the electrons can be done by using for example
Heat thermal electricity magnetism electromagnetism chemicals electrochemistry pressure p0 electricity light photoelectricity
What is one microhm equal to
0.000001 homes
What is 1 mlliohm equal to
0.001 ohms
What is 1 mega ohm equal
1 million ohms
What is 1 megabytes equal to
1 million volts
Branch circuits in dwelling units shall not have a voltage exceeding blank to ground with the exception of a BNC rule 2 - 110 circuit voltage to ground dwelling units
150 volts
A circuit has 90 volts 20 amps what is R
4.5 ohms
How many milli amps can kill you?
50 mA
What is meant by strength of a coil magnetic field
A closely round coil create the stronger magnetic field
What type of circuits allow current to flow through more than one complete piath
A parallel circuit
What is electrochemistry
A voltaic cell is made by immersing two different metal electrodes in a chemical solution called electrolyte
Who responds better to artificial respiration a victim of high voltage shock or low voltage shock
High voltage
What is defined as high voltage
Above 750 volt
Blank on the other hand regularly reverses direction and occurs when the polarity of each end of the conductor is reversed which is always the case with most current
Ac alternating current
What does a load do.
Alowed use electrical energy to do use for work such as producing motion light or sound or to provide heating
In North America electrical energy is produced and transmitted as blank blank with a frequency of blank hurts
Alternating current flows in one direction for one 120th of a second and then in the other direction for one 120th of a second 60 Hertz
Factors affecting electric shock blank blank blank blank blank blank
Amount and path of current type of voltage AC or DC value of voltage length of time the body is energized condition of the skin area of the skin
What are the laws of a series circuit
Amperage is consistent resistance is the sum of all loads in the circuit. RT= R1+R2+R3 Volts in a series circuit ET Total the sun of the voltage drop across each load in the circuit.
What does a simple electrics circuit consist of
An energy source conductor and load.
Which victims respond better to CPR high or low voltage
High voltage victims
Why must an ohmmeter never be connected into a live circuit
Could damage ohlmeter an batteries could explode.
How does a closely wound coil affect ghd magnetic firld
Creates a stronger magnetic field.
What are the three all ohms law equations.
I=EoverR or R=E over I or E=I XR
When current flows in a constant direction it is called blank
Direct current DC
which current only flows in one direction
Direct current DC
When using the olm meter what must be done before you can use this meter
Disconnect circuit power and discharge all high voltage capacitors before testing resistance continuity diodes or capacitance.
When electrons are made to move in the same direction they produce blank blank
Electric current
What produces electricity by electromagnetism
Electric generator
Two different metal electrodes in a chemical solution is called blank
Electrolyte
Electric generator produces electricity by blank
Electromagnetism
How do you calculate values in a series paralell circuit?
Total circuit resistance total line currant voltage drops across the series componamts branch current flow? I
True or false high voltage electricity can arc or jump across an air gap from one point to another if the voltage between the two points is strong enough for this reason personnel must remain well clear of high-voltage equipment
True
True or false thermocouples are often use a thermometer to detect and measure temperature the current produced by a thermocouple is enough to hold in a small electro magnet within a gas valve indicating the presence or absence of a pilot flame
True
True or false starting capacitors ratings are from 75 to 600 microfarads and with voltage ratings of 110 volts to 3330 volt
True it takes the charge wacks the fan to start working