Electrostatic Flashcards

(92 cards)

1
Q

What is electrostatics?

A

it is the study of resting or stationary electric charges

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2
Q

what is a ground?

A

it is a connection made to the earth. It has a potential of 0

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3
Q

Electrification is a process of ___ or ____ electrons from the body

A

adding, removing

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4
Q

How do you transfer electrons from one object to another?

A

Through means of Friction, or rubbing

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5
Q

When friction occurs, two things happen…

A
  1. the object the electrons are transferred to are negatively charged
  2. the object losing the electrons are now positively charged
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6
Q

What is the most fundamental means of electrification?

A

Friction is the most simplest means

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7
Q

Do electrons need contact to travel?

A

No it does not

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8
Q

Every charged body is surrounded by ____ field called an _____ _____

A

force, electric field

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9
Q

Electric field can cause ______

A

induction

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10
Q

If you have one strong charged object and one weak charged object, what do their electrical fields do when they start to get close to one another?

A

The charges will move to one end of an object.

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11
Q

When you induced the balloon with electric, what two things are happening with the protons and electrons of the balloon and the wall?

A

The electrons in the balloon are attracted to the protons inside of the wall, but the electrons that were inside of the wall are now pushed deeper b/c it is repelling the electrons from the balloon. Attraction and Repulsion working

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12
Q

How many parts are there to the laws of electrostatics?

A

5

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13
Q

what is the first part of the laws of electrostatics?

A

Repulsion and attraction

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14
Q

2nd part of the laws of electrostatics?

A

inverse square law - which states that the force between two charges are proportional to the product of their power and it is “inversely” proportional to the squared distance between them. It is also known as the Coulomb’s law of electrostatics. Literally, the closer the distance, the more force produced, the further the distance the less force produced.

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15
Q

Part 3 of the laws of electrostatics?

A

Distribution, states that charges can be found on the surfaces of the conductor, not the middle of the conductors. This is due to the repulsion between electrons or like vs like repulsion rule.

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16
Q

part 4 of the laws of electrostatics?

A

movement, along electrons can move along the solid conductors, protons and neutrons are fixed. Nuclei are tightly bound.

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17
Q

part 5 of the laws of electrostatics?

A

Concentration - The most amount of charge (electrons) can be found on the surface where the curvature is the greatest. Electric charges like to collect in a group near the region of the sharpest curvature.

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18
Q

what is a static discharge?

A

Static discharge is when an opposite charged objects are in close range. The electrons will jump to that object in a form of a static discharge

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19
Q

when does static discharge occur?

A

when the difference in charges become great, lots of electrons and protons activities, and the distance between them decreases.

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20
Q

what happens when static discharge occur?

A

it releases excess energy in a form of light photons and an audible sound.

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21
Q

what causes tree branched artifact?

A

static discharge

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22
Q

what is electrodynamics study?

A

it is the study of electric charges in motion

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23
Q

when does the charge flows?

A

when there is a potential difference across the ends of a conductor

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24
Q

what is potential difference?

A

Force/strength of electron flow

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25
what is another name for Potential difference?
EMF, Electromotive force (force of moving electrons)
26
What is the characteristic of the potential difference?
the greater the amount of electrons exists at one point and a deficiency of electrons at another the greater the attraction between these points
27
what is the unit of measurements for Potential Difference/EMF?
Volt
28
How is voltage abbreviated in electrical equation?
"E"
29
Potential difference is defined as _ joule of ____ ____ on _ coulomb of charge (1 volt = _ joule/_coulomb)
1, work done on, 1. | 1 volt = 1 joule/1coulomb
30
what is a current?
flow of electrons through a conductor
31
what is the intensity of electric current determined by?
by number of electrons flowing past a point in one sec
32
What is the unit of measurement for current?
Ampere
33
In ampere, it consists of movement of ___ x __ to the __ power / second
6.24x10 to the 18, power per second
34
How many types of current are there?
2, Direct Current and Alternating Current
35
How do you describe a Direct Current?
When the electrons flow in the same direction.
36
in Direct current, it can be said that it is _____
pulsating DC
37
how do you describe alternating current?
alternating current have electrons move first in one direction and then it reverses and move the electrons in the other direction. this is all through a single conductor
38
Alternating current can be said to be _______
oscillating
39
What is resistance?
It is the amount of opposition to the flow of electrons in an electric circuit. how many obstacles do the electrons have to encounter?
40
what represents the resistance?
the omega sign.
41
what is the unit of measurement for resistance?
ohm
42
what is resistance dependent upon?
1. Type of material the conductor is made of 2. Physical dimension of the material 3. Temperature. The higher the temp the higher the resistance
43
Material's conductivity is determined by
Material's atomic structure
44
In physical dimensions of material have to do with the resistance?
Length of the conductor affects the resistance. The longer the conductor, the higher the resistance. Thickness of diameter of conductor affects the resistance. The higher the cross section diameter of the conductor, the less resistance there is.
45
what is an electrical circuit?
it is a pathway that allows the electrons to travel in a complete circle from their source. There will always be resistance which they'll meet.
46
what are the three essential requirements for the circuit to work?
1. A source of electromotive force, aka potential difference 2. A conductor 3. A resisting device to control the rate of current flow.
47
Draw Ohm's law the best you can.
(draw)
48
what does a wave form in Direct Current looks like?
a straight line
49
what does a wave form in Alternating Current looks like?
a sine curve
50
DC does this and AC does this
pulsating and oscilliating
51
how many types of circuits are there? and what are they?
2, series and parallel circuits
52
what is unique about series circuit?
it has only one path for current to travel. All parts are connected to the end, so if there is a break anywhere, it is now consider to be an open circuit and the current stops.
53
what does the body of the "rocket" looks like?
VIR, V is + in series and = in para, I is = in series, and + in para R is + in both series and para with denote of 1/R
54
what is unique about parallel circuit?
in parallel circuit, there are more than one way for the current to flow. Components are like roots from the main circuit. There can still be a flow of current when there is an interruption of a pathway.
55
What is a voltage drop?
it is a potential difference across a resistor. It's like paying toll gate, do you have enough "money"/voltage to get through all the resistors in the circuit? EACH time a voltage passes through a resistor in the circuit, it loses its voltage to those resistors.
56
How do you determined the voltage drop?
ONLY in series circuit, you can find out what the total voltage is, which is the amount you have to "spend" to get through each resistor. Then you must find out the actual voltage drop per each resistor. It may varies as each resistance have different ohms.
57
what is an electric generator?
it is a generator that turns mechanical energy, (energy of movement) into electrical energy by using Faraday's discovery of moving flux lines in relationship to the conductor to induce electrical current.
58
what are the components of electric generator?
magnets, armature, slip ring, stationary brushes
59
what is an armature?
it is a conductor, a coil of wire set between opposing magnetic poles (N and south), so that it encounters the strongest line of force.
60
what are slip rings?
2 metallic rings isolated from another. They rotate with Armature and each ring attaches to one end of the armature wire.
61
what are brushes?
Brushes are metal strips which conduct current from the armature and transmit it to the external circuit
62
what is electrical symbol for AC?
----0 ~ 0--------
63
what is the unit for frequency?
hertz
64
american and Canadian generators operates at __ hz AC, at __ cycles per second
60 Hz AC, 60 cycles per second
65
How many alternations does one cycle have in the generator?
2 alternations.
66
One alternation is equal to ___ cycle
1/2
67
What is single sine curve represented by?
single phase of AC
68
what is the average value of the amplitude in AC generator?
63.7%
69
how do you calculate the average value of a half cycle?
0.637 times the peak value
70
what is used in radiography to express peak values?
kilovoltage
71
voltage is not constant in DC, because of drops, therefore pulsating DC produces a
ripple effect
72
in series circuit, total resistance is equal to
the sum of of the separate resistance
73
in series circuit, the current is
the same throughout the circuit
74
Voltage drop is specific to series circuit, it is the potential difference across a resistor. What does it determine in regards to voltage?
if the amount of voltage on the circuit has enough required to push a specific amount of current across a resistor
75
what must voltage drops be summed up to?
the voltage of the source
76
What does the power formula state?
that total power is the sum of power consumed by each resistor
77
In Parallel circuit, total resistance is always ____ than the ____ valued resistor
less, lowest
78
how is the total resistance value calculated in Parallel circuit?
1/Rt= 1/R1+1/R2+1/R3
79
in parallel circ, how is the current calculated?
total sum of the circuit is the equal sum of current in each branch
80
voltage is the ___ in all branches of parallel circuit
same
81
power in circuit is the ___ of all power consumed in each branch
sum
82
in a simple generator, what angle provides the peak EMF?
when the armature reachesthe 90 degrees
83
When is there no no EMF produced in a simple generator?
when it is at 0 degrees.
84
what is the average value of a half cycle?
.637 times the peak value
85
What are the advantages of AC over DC
1. the AC has current flowing in different directions to provide the changing magnetic field that induces voltage in the secondary coil. 2. less power loss in AC to DC.
86
What is the function of a transformer?
to transform the electric current to higher or lower intensity.
87
what are the parts of transformer?
it has a primary coil and secondary that are not touching.
88
What is primary coil of transformer connected to?
it is connected to an electric source given by alternating current.
89
what is the secondary coil of transformer connected to?
it is connected to an output source. The secondary coil develops AC as well from the primary coil.
90
When voltage is increased from primary coil to the secondary, it is called
Step up transformer
91
when voltage is decreased from primary coil to the secondary, it is called
step down transformer
92
what are the difference types of cores of transformer? which one is strictly used with X ray
Air core, open core, closed core, and D shell core(this one is used with x ray)