Home > Flashcards > Print Preview
The flashcards below were created by user
natalieplana
on FreezingBlue Flashcards. What would you like to do?

What is Coloumb's law? (equation) What does it mean?
describes force between two charges
F = k (q1q2) / r
k = 9 x 10^{9}

Coloumb's law resembles what? But?
gravitational force (G)(m _{1}m _{2})/(r ^{2})
 but, gravitational force is attractive
 electrical force is repulsive

electric field  in what way are the lines drawn? What does the length of the line indicate?
(+) > ()
length = strength
(smaller is stronger)

What is the electric field created by charge Q?
E = k x (Q)/(r^{2})

What is the force felt by charge q in the electric field E?
F = E x q

What makes and feels the field?
Q makes the field
q feels the field
[F = k x (Qq)/(r^{2})

What is the potential energy of of the charge in electric field?
Potential energy (U) = force x displacement (like ugh)
U = Eq x h

How does potential energy change when moving perpendicular to electric field?
doesn't change
same way that moving parallel to surface of the earth doesn't change gravitational potential energy

What is an electric dipole?
created by 2 opposite charges with equal magnitude

(+) and () fall/rise to lower/higher potential?
+ charge falls to a lower potential
 charge rises to a higher potential

high/low potential and +/ potenital
 high potential = + potential
 low potential =  potential

How do we measure movement of a charge?
current (A)

So, what is current? (How is it measured)
Coloumbs/second

Current flows in what direction (relative to potential energy)
current flows from high potential to low potential

In what direction does current flow (relative to electron flow or electron velocity)?
current moves in opposite direction of e^{} flow

conducting electricity: what are good conductors and poor conductors?
 good = allow e^{} to flow freely [metals]
 poor = hold e^{ }tightly in place [resistors]

What is induction?
charging a conductor

circuit equations: current, voltage, resistance, capacitance
V = IR
I = Q/t
C = Q/V

what is capacitance?
ability to store charge per unit voltage [Q/V]

voltage is the same thing as...... and it depends on
potential energy
depends on distance

plates that are further apart will have greater/less voltage and capacitance?
greater voltage
less capacitance

What is a capacitor?
temporarily stores energy in a circuit

What is the separation of charges in a capacitor?
emf between the plates

what is resistance?
resistance to flow of charge

resistance is directly proportionate to what?
length of wire
[R = density x (length/area)]

resistance and temperature
resistance increases with temperature
[thermal oscillations impede with flow]

Kirchoff's Rules:
 amount of current flowing in and out
 voltage around the circuit
battery
 amount of flow in = amount of flow out
 votalge around any path in circuit must sum = 0
 battery adds energy to circuit

How does battery add energy to the circuit?
increases voltage from one point to another
(emf = voltage added)

Diaelectric constant (K)
substance between plates of a capacitor
 must be insulator to separate charge
 resists creating EF, in order to store energy

Resistors in series/parallel
what is constant?
series = add [current is constant]
parallel = 1/R [voltage is constant]

what is the terminal voltage? (equation)
V = emf  IR

AC Current  what's going on?
e^{} don't move in one direction,
they oscillate back and forth

maximum current and maximum velocity in an AC Current
V_{max} = sqrt.(2) x V_{max}
I_{max} = sqrt.(2) x I_{max}

What creates a magnetic field?
charging electric field
currents (moving charges) creates the magnetic field

+ and  of electric field corresponds to what in magnetic field?
north and south
north = + and south = 

In what direction do magnetic lines point?
north > south

Doess a stronger magnetic field have closer lines, or further apart?
closer lines = stronger fied

How does the KE of a particle moving through the magnetic field change?
no work done by the magnetic field, means no change in KE due to the magnetic field

What is magnetic force?
F = q x V x B x sin(0)

force is applied in what direction relative to both velocity and magnetic field
force is perpendicular to both velocity and magnetic field

What is the work done by magnetic force?
no work:
because it's perpendicular to velocity

What way does magnetic field act?
like centripetal force (mv^{2}/r)
because charged particle moves in a circle

What will move through a magnetic field with a smaller radius: a proton or an electron
electron:
because it has smaller mass [F = mv^{2}/r]

Right Hand Rule
thumb = direction of current
fingers = direction of magnetic field
palm = direction of force

What results from a change in magnetic field?
an electrical field

What happens to the mechanical energy in a magnetic field when it is changed and creates an electric field?
mechanical energy to create the field is dissipated as heat

What is the magnetic flux?
number of magnetic fields running through the loop

what does change in magnetic flux do?
induces an emf

What is a magnetic field generated by?
a moving charge

moving charge experiences what when moving through a magnetic field?
force = qvBsin0

In what direction is this force?
perpendicular to velocity and magnetic field (B)

At equilibrium, in an electric and magnetic field, what is the net force acting on a particle?
0
force from electric field = force from magnetic field
Eq = qvBsin(0)

How can we find the acceleration or distance of a particle traveling through an electric or magnetic field
F = ma
set force (Eq) or (qvbsin) = mass x acceleration
distance = (1/2)at^{2}

