Question | Answer |
Define Electrostatics. | The study of electrons at rest |
Define Electrodynamics. | Electrons in motion (current flow) |
Define electrification. | Gain or loss of electrons from matter. |
Three types of electrification. | Friction, Contact, Induction. |
Define friction and state whether or not it confers the same or opposite charge. | rubbing, same charge |
Define contact and state whether or not is confers the same or opposite charge. | touch, same charge |
Define induction and whether or not it confers the same or opposite charge. | No contact between objects, opposite charge |
What is a coulomb? | unit of electric charge |
1 coulomb is equal to ____ electric charges | 1 C = 6.3 x 10^18 electric charges |
What is the difference between electrification and ionization? | Electrification is a gain/loss by matter whereas ionization is a gain/loss by an atom. |
Finish this law Unlike charges__________, like charges _____________ | attract, repel |
Finish this law Electrostatic force is _____ _____ to the product of the electrostatic charges and ______ proportional to the square of the _______ between them | directly proportional, inversely , distance |
What is the previous law also known as? | Coulomb's |
Finish this law When an object is electrified, the ______________ | the e- are distributed evenly within or outside the object. |
Finish this law The charge is more concentrated ________________ | along the sharpest curve of the surface. |
Flow of electrons | Current |
What is the unit of measurement of Current? | Amp |
What is a circuit? | Pathway for current to flow (has to be closed to flow) |
What do we use to set our tube current? | mA (1/1000 of amp; milliamps) |
Potential difference is _______. | where you have an excess of electrons at one end and deficiency at the other end |
What is the unit of measurement for potential difference? | voltage |
What do we use to set our potential difference within the tube? | kV (kilovolt- average energy), keV (kiloelectron volts - pot.diff. of each individual electron), kVp (kilovolt peak - max. potential diff. that you set) |
Name four states of matter. | Conductor, insulator, semiconductor, superconductor |
Give an example of a semiconductor. | silicon, germanium, arcelin |
Which state of matter does not allow current to flow due to very high resistance? Give some examples. | insulator (rubber, glass, non-sap wood) |
No resistance, allows free flow of current without potential difference. Cold temps. required. Which state of matter is being described? | superconductor |
Copper, aluminum, silver and gold are examples of what state of matter? | conductor |
Give examples of a superconductor. | niobium, titanium |
Path for current to flow with a potential difference. | Circuitry |
What are the two types of circuitry? | open and closed |
Which circuit does not allow flow of current? | open circuit |
Name five sources where current can come from. | battery, dynamo, solar, atomic, geothermal |
Which source converts mechanical energy into electric energy? | dynamo |
Source that converts chemical energy into electrical energy. | battery |
What are the four conditions in which current will flow? | vacuum, gas, ionic solutions,metallic conductor |
What is resistance? | opposition to current flow |
Wht is the unit of measurement for resistance? | ohm |
what four factors determine resistance? | type of material, length, diameter, temperature |
What material would be considered an insulator or ground? | glass or rubber |
Length and resistance have a/an ______ relationship. | directlonger the length, more resistance |
Diameter and resistance have a/an ____ relationship. | indirectsmaller the diameter, more resistance |
Temperature and resistance have a/an ____ relationship. | directhotter temp. , more resistance |
Name some components of a circuit. | resistor, battery, capacitor, ammeter, volmeter, switch, transformer, rheostat, diode, transistor |
This component of a circuit stores electrical charge temp. | capacitor |
What is the unit of measurement for the capacitor? | Farad |
These two components of the ciurcuit measures amperage and voltage. | ammeter, voltmeter |
This component of the circuit controls mA. | variable resistor |
Which component of the circuit allows us to select our kVp? | autotransformer |
What are the two sides of a circuit? | primary (low voltage) and secondary (high voltage) |
Opens/closes main circuit and is located on the primary side of the circuit | switch |
What are the two most important components on the secondary side of the circuit? | tube and rectifiers |
Solid state device that converts alternating current into direct current. | Rectifiers |
step-up or high voltage transformers | converts voltage into kilovoltage; divided between the primary and secondary sides |
Over head tube works at _____ or _____ while the undertable tube works at ______ or _____ | 3-5 amps or 6-10 volts; .5-5 mA or 6-10 volts |
Rotor motor | turns the rotor on |
Name the two types of circuits? | series or parallel |
Series circuit | all elements are connected in line along the same conductor. |
Parallel circuit | contains elements that bridge conductors |
Ammeters always connected in ____ circuit while voltmeters are always connected in _____ circuit. | series, parallel |
What is the advantage of having a parallel circuit? | If one section of the circuit does not work the rest of the circuit will still function |
What is the formula for Ohm's Law? | V= IR |
Solve this problem.V (voltage) = 220 v ; I (amperage) = x ; R (resistance) = 10 | I= 22 amps |
Direct current | electrons flow in one direction only |
Electrons alternate in different directions like sine waves. | Alternating current |
Wavelength | distance from crest to crest or trough to trough |
What is the unit of measurement of wavelength? | angstroms |
Frequency is the _______. | number of wavelengths |
______ is the unit of measurement of frequency. | hertz |
Height of a wave. | amplitude |
Rate of doing work. | Power |
What is the unit of measurement for power? | watt |
What formula is used to determine total power? | P= IV(I= amperage, V= voltage) |
Solve this problem. I = 120 ; V= 1.5; what is the total power? | P=IVP=120(1.5) = 180 watts |
due to heat resistance. | Power loss |
What formula is used to determine power loss? | P = I^2R |
State the formulas for the following:ohm's law, power, power loss, total resistance in a parallel circuit | Ohm's law - V=IRPower - P=IVPower loss - P=I^(2)RTotal resistance in a parallel circuit - 1/Rr = 1/r1 + 1/r2 + 1/r3 |
__________ occurs because of the movement of negative electric charges. | Electrification |
Differentiate between static electricity and electrodynamics. | Static electricity is the study of electrons at rest. Electrodynamics is current flow (charges in motion) |
Friction causes a/the ______ charge to be transferred to an uncharged body. | same |
Contact causes a/the _______charge to be transferred to an uncharged body. | same |
Induction causes a/the _____ charge to be conferred to an uncharged body coming into the field of a charged body. | opposite |
Give an example of the following:insulator material, conductor material, semiconductor material | insulator - rubberconductor - aluminumsemiconductor - silicon |
What is the standard international unit of electrostatic charge? | coulumb |
Define potential difference and state unit of measurment. | excess of electrons at one end and a deficiency at the other end unit: voltage |
Define tube current and state unit of measurment. | flow of electrons within tube unit: mA |
Define filament current and state unit of measurment. | flow of electrons to the filament unit: amps |
Define resistance and state unit of measurment. | opposition to current flowunit: ohms |