Electricity

Question 1

Measuring force of attraction of repulsion between charged objects

Answer 1

F = kq1q2/r^2

coulombs

Question 2

Universal Law of Conservation of Charge

Answer 2

Universe has no net charge

Question 3

What is the smallest possible unit of charge?

Answer 3

one electron unit which is 1.6 X 10^-19 C, the charge on one electron or one proton

Question 4

Center of charge

Answer 4

Where the charge is considered to have thought to be originated even though there may be no charge at it.

Question 5

What is a Field

Answer 5

Distortion in space that creates a force on a charge. This force created by fields can act at a distance

Question 6

What is an electric field

Answer 6

Electrostatic force per unit charge (N/C, V/m)

Question 7

What is force of an electric field?

Answer 7

F = Eq

Question 8

Potential energy of a charge in an electric field

Answer 8

U = qEd

on earth

Question 9

Voltage

Answer 9

Potential for work by an electric field in moving any charge from one point to another given in units of volts (V = J/C). Voltage is scalar so voltages can be summed up directly.

Voltage = PE/q = E*d

Question 10

Voltage due to a point charge

Answer 10

V = k q1/r

Question 11

Is Work done by an electrostatic field path dependent? Why or why not?

Answer 11

Path independent

Electric field is conservative; conserves mechanical energy

Question 12

Equipotential surfaces

Answer 12

points perpendicular to an electric field. All points on an equipotential surface are at the same voltage.

Question 13

Electric dipole moment

Answer 13

p = qd

Question 14

Current

Answer 14

Moving charge given in amps (A = C/s)

scalar, flow to be in the direction of the movement of positive charge

i = V/R, or VIR

Question 15

Circuit

Answer 15

a cyclical pathway for moving charge where a battery provides the potential difference (voltage) needed to maintain charge flow

Question 16

Resistivity

Answer 16

Resistance to the flow of charge

Question 17

Resistance (R)

Answer 17

quantitative measure of an object of a particular shape and size to resist the flow of charge. Measured in ohms.

wires that are long and have a great cross sectional area have the greatest resistance

Question 18

Flow rate of a real fluid moving through a horizontal pipe with constant diameter

Answer 18

Q = change in pressure / resistance

Question 19

Battery

Answer 19

adds energy to a circuit; battery pumps the fluid to a greater height and rated by EMF, another word for voltage

Question 20

Capacitor

Answer 20

temporarily store energy in a circuit; stores it in a form of separated charge

Question 21

Parallel plate capacitor

Answer 21

two plates separated by a very small distance. One plate holds positive charge, and the other plate holds the exact same amount of negative charge. This separation of charge creates an electric field that is constant everywhere between the plates

Question 22

Electric field in a parallel plate capacitor

Answer 22

q/dielectric times Q/A

greater the area, greater the charge, greater the electric field of the plate capacitor

Question 23

Capacitance

Answer 23

the ability to store charge per unit voltage; something with a high capacity can store a lot of charge at low voltage

C = Q/V

Question 24

Amount of charge that can be stored directly on each plate in relation to area, and distance

Answer 24

Greater the area, greater the amount of charge that can be stored on each plate

The farther the plates are separated, the greater the voltage, and lower the capacitance

Question 25

Energy stored in any shape capacitor

Answer 25

U = 1/2 (QV) = 1/2 (CV^2) = 1/2 (Q^2/C)

Question 26

in a fluid capacitor, what would a g*change in height be equal to?

Answer 26

voltage

Question 27

dielectric in a capacitor

Answer 27

An insulator lodged between the plates to break the circuit and store energy in the circuit. Case of no battery: Increase capacitance by decreasing the voltage - the negatives and positive lined up in the capacitor get canceled by the molecules that are polarized in the dielectric. Battery inserted: increase capacitance by increasing the charge stored. When the battery is inserted, the battery tries to make the voltage the same across the circuit. So it inserts more charge to compensate for those charges that are canceled out.

Question 28

dielectric of a non-conducting material

Answer 28

always greater than 1

Question 29

The point of some maximum voltage the dielectric will break down and conduct electricity

Answer 29

the dielectric strength

Question 30

Resistors in series

Answer 30

Total resistance is R1 + R2 + ...

Question 31

Resistors in parallel

Answer 31

1/R = 1/R1 + 1/R2 + ...

Question 32

Capacitors in series

Answer 32

1/C = 1/C1 + 1/C2 + ...

Question 33

Capacitors in parallel

Answer 33

C = C1 + C2 + ....

Question 34

Electric potential, V Voltage is a "difference in electric potential" Scalar or vector?

Answer 34

Potential for work by an electric field in moving any charge from one point to another - random numbers in space V = Ed = PE/q Voltage due to a point charge: kq1/r: q creating that voltage) = J/C or Change in unit is Volts scalar quantity

Question 35

Electromagnetic field

Answer 35

Light change in E creates a change in B, change in B then creates a change in E, E and B are perpendicular to each other propagating outward creating a wave of its own independent existence in direction of velocity, c = 3*10^ they can travel through a vacuum; don't need a medium

Question 36

Potential energy from electric field derived from a point charge

Answer 36

U = kq1q2/r

Question 37

Dipole in an electric field

Answer 37

align itself opposite orientation to the field

Question 38

Magnetic field

Answer 38

unit: tesla = Q*v*B produced only by moving charges so a moving charge creates or induces both magnetic and electric field exerts a centripetal force on a moving particle qBv = mv^2/r non-conservative force

Question 39

Does magnetic field create force on a static electric charge?

Answer 39

Nope

Question 40

T/F A moving charge induces both a magnetic and electric field

Answer 40

T

Question 41

Why doesn't a moving charge through a magnetic field increase its speed?

Answer 41

Because no work can be done by the force (cos 90 = 0) and W = F*d cos(0). This force does no work so it cannot transfer energy to the particle to increase the speed of the particle.

Question 42

Why does a charged particle moving through a magnetic field go through a circular path?

Answer 42

Magnetic force perpendicular to both the velocity and magnetic field causes the particle to go onto a circular path

Question 43

gyroradius

Answer 43

The radius of the circular motion of a charged particle in the presence of a uniform magnetic field. r=mv/qB .

Question 44

Electric potential energy

Answer 44

PE = F*d = qEd