Term
| Process of electron charges being added to or subtracted from an object is.... |
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Definition
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Term
| The process where like charges repel and unlike charges attract. |
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Definition
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Term
| The mathematical formula for electricity where the force between 2 objects is inversely proportional to the square of the distance between them is called.... |
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Definition
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Term
The 5 laws of electrostatics:
(list in order) |
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Definition
1) Repulsion attraction
2) Inverse Square Law
3) Distribution
4) Concentration
5) Movement |
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Term
| This is called ___________ when charges reside on the external surfaces of conductors and equally throughout nonconductors. |
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Definition
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Term
| This is called ______________ when one object is rubbed against another, resulting in electrons traveling from one object to the next. |
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Definition
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Term
| This is the process of electrical fields acting on one another without contact. |
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Definition
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Term
| What is it called when electrons are moving predominantly in the same direction? |
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Definition
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Term
| A space from which air has been removed. |
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Definition
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Term
| Materials that facilitate electron flow are called..... |
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Definition
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Term
| List 2 materials that act as conductors. |
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Definition
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Term
| Non-conducting materials are termed.... |
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Definition
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Term
| These are examples of insulators. |
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Definition
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Term
| How do you spell.....silicon or silicone? LOL |
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Definition
Silicon
Silicon germanium is used to make semi-conductors |
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Term
| This is a pathway that permits electrons to move in a complete circle from their source, through resisting electrical devices and back to the source. |
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Definition
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Term
| This converts chemical energy to electrical. |
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Definition
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Term
| This converts mechanical energy to electrical. |
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Definition
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Term
| This converts solar photons to electrical energy. |
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Definition
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Term
| These convert nuclear energy to electrical energy. |
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Definition
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Term
| In a current flow, do electrons move from highest concentration to lowest concentration....or lowest to highest? |
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Definition
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Term
| The quantity of electrons flowing within a given amount of time is called... |
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Definition
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Term
| Current is measured in what unit? |
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Definition
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Term
| The difference in number of electrons in excess at one end of the circuit and deficiency at the other end is called.... |
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Definition
Force
Strength
Potential Difference
....all the same |
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Term
| Potential difference describes the force or strength of electron flow and is measured in....? |
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Definition
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Term
| The amount of opposition to current within the circuit is called..... |
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Definition
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Term
| Resistance is measured in.... |
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Definition
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Term
Directly or Indirectly Proportional?
The resistance and length of a conductor |
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Definition
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Term
Indirectly or Directly Proportional?
Resistance and diameter of the conductor. |
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Definition
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Term
| Heat varies in its relationship with..... |
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Definition
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Term
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Definition
| The current along a conductor is proportional to the potential difference (force). |
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Term
| Ohm's law is expressed in the algebraic form as: |
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Definition
V=IR
V = potential difference in Volts (force)
I = current in Amperes
R = resistance in Ohms |
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Term
| Name the kind of circuit sends electrons through various resistance devices by linking them one after another. |
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Definition
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Term
| This kind of circuit provides each resistor with an individual branch. |
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Definition
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Term
| The total amount of power used in an electric circuit is called a..... |
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Definition
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Term
| This occurs when materials have the ability to attract iron. |
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Definition
Magnetic force
note: When a charged particle is in motion, a magnetic force field perpendicular to the motion will be created. |
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Term
| Force fields created from magnets are called magnetic fields. What are two other names for this? |
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Definition
Lines of Force
Lines of Flux
Magnetic Fields - all the same! |
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Term
| Lines of force always flow from N to S outside a magnet. In which direction do they travel on the inside of a magnet? |
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Definition
S to N
Note: They will never intesect |
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Term
| The stronger the magnetic field, the greater are the number of ____________ __ _________. |
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Definition
Lines of Flux
aka: Flux Density |
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Term
| What is the SI (System International) unit for magnetic flux? |
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Definition
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Term
| How many Gauss' in 1 Tesla? |
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Definition
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Term
| What are the three (3) production classifications for magnets? |
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Definition
1) Natural Magnets
2) Artificial Permanent Magnets
3) Electromagnet |
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Term
| This type of magnet is produced over time when natural iron forms within the earth. |
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Definition
Natural Magnets
aka: Lodestone |
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Term
| This type of magnet is manufactured from a composition of metals which hold permanent charges. |
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Definition
Artificial Permanent Magnets
Note: they are made from aluminum, nickel, cobalt (Alnico) |
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Term
| These are temporary magnets produced by moving electric current. |
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Definition
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Term
| List the three pertinent laws of magnetism. |
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Definition
1) Law of Repulsion/Attraction
2) Inverse Square Law
3) Magnetic Poles |
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Term
Name the law when:
Like poles repel, unlike poles attract |
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Definition
Law of Repulsion/Attraction
Note: Also, lines of force moving in the same direction repel, and moving in opposit directions attract |
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Term
| When electric fields radiate out from a positive and travel towards a negative charge...which law does this associate with? |
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Definition
| Law of Repulsion/Attraction |
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Term
Name the law:
Intensity of magnetic force is inversely proportional to the square of the distance between them |
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Definition
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Term
Name the law:
Every magnet has a north and a south pole. No matter how many times it is divided, it maintains the poles. |
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Definition
Magnetic Poles
aka: Dipoles |
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Term
| This can be achieved when non-magnetized metal temporarily aligns its poles with nearby lines of force from a magnet. |
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Definition
Magnetic Induction
note: Once that magnet is removed, the poles slowly return after a period of time to a random arrangement. |
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Term
| The ease at which material can be magnetized is termed... |
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Definition
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Term
| The ability of material to stay magnetized is called... |
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Definition
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Term
List the 4 types of Retentivity
(the ability of material to stay magnetized) |
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Definition
1. Ferromagnetic
2. Paramagnetic
3. Diamagnetic
4. Nonmagnetic |
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Term
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Definition
| Ferrous metals (Iron, cobalt and nickel) are highly permeable and greatly susceptible to induction. |
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Term
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Definition
| Platinum and aluminum - low permeability and weak attraction to magnetic fields |
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Term
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Definition
Beryllium, bismuth and lead - weakly repelled by all magnetic fields including north and south poles.
Note: Water is also a diamagnetic material |
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Term
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Definition
| Wood, flass, rubber, and plastic - not affected by magnetic fields and cannot be magnetized. |
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Term
| This is created when a current flows through a coiled wire. |
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Definition
Solenoid
note: The strongest magnetic force will be inside the coil |
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Term
| A solenoid with an iron core is called a...... |
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Definition
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Term
| The strength of solenoids and electromagnets is determined by the number of loops of wire, the current strength applied to the wire, and the _______________ of the core. |
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Definition
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Term
| The three factors that influence the effectiveness of solenoids or electromagnets are... |
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Definition
1. diameter of the coil
2. length of coil
3. current passing along the coil |
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Term
| This occurs when two coils are place in proximity and a varying current supplied to the first coil induces a similar flow in the second coil. |
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Definition
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Term
| This is a device that function to convert mechanical energy to electrical energy. |
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Definition
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Term
| This is a device that is supplied with electrical current to produce mechanical motion. |
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Definition
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Term
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Definition
Alternating Current
Direct Current
note: & a great rock band! ACDC |
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Term
| This is composed of two coils placed near one another (without an electrical connection) that operates by mutual induction. |
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Definition
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Term
| Describe a Step-Up transformer |
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Definition
| More turns in the secondary coil than the first |
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Term
| Describe a Step-Down transformer |
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Definition
| More coils in the primary coil than the secondary coil |
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Term
| State the Transformer Law. |
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Definition
All transformers must operate on AC.
Note: this is a T/F question on test |
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Term
| State the Transformer Law Formula |
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Definition
Vs Ns
=
Vp Np
V = Voltage
s = secondary
p=primary |
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Term
| Currents that oppose the magnetic field which is inducing them is called... |
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Definition
Eddy current loss
note: like a big boulder in a stream and the water goes around it |
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Term
| This loss occurs as the changing current used with AC reverses magnetic fields back and forth producing resistance. |
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Definition
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Term
| This loss is inherent resistance to current flow found in all conductors that results in heat generation. |
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Definition
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Term
| Autotransformers operate on what type of induction? |
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Definition
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Term
| This device can accumulate and store an electrical charge |
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Definition
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Term
True or False
X-ray tubes operate best using DC, but the transformers operate on AC. |
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Definition
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Term
| X-ray tubes operate best using DC or AC current? |
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Definition
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Term
| Transformers operate on DC or AC current? |
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Definition
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Term
| This is the boiling off of electrons at the cathode end of the tube. |
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Definition
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Term
| This is AC on the secondary side of high voltage step-up transformer. |
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Definition
Unrectified voltage
note: Not changed to DC yet. Only the positive portion of the wave is useful in the x-ray tube, but cannot be applied yet. |
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Term
| This occurs when the rectifier does not conduct current during the negative portion of the wave, and current can now be safe to administer to the x-ray tube. |
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Definition
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Term
| Alternating Current (AC) is represented by what? |
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Definition
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Term
| This process uses four diodes and reverses the negative wave from AC, making the output voltage to the x-ray tube always positive. |
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Definition
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Term
| Who discovered the link between electricity and magnetic fields? |
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Definition
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Term
| Who wanted to see if a magnetic field could induce electricity? |
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Definition
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Term
| What is the most popular type of transformer? |
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Definition
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Term
| The two units for magnetic flux density are... |
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Definition
Tesla (T) and Gauss (G)
1T = 10,000 G |
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