Electrostatics Flashcards
1
Q
Electric Field effects on charged particle
A
- can accelerate the particle from rest
- do work on a charged particle
- moving charged particles are deflected by perpendicular e.fields
- F=qE
2
Q
magnetic effects of charged particle
A
- moving charged particles traverse in a circle thru perpendicular magnetic fields
- do not accelerate charged particle from rest
- do no work on a charged particle
- depends on speed of particle and magnitude of charge
3
Q
When voltage is applied to a wire with no net charge, what will the resulting net charge be?
A
- current will make electrons flow into and out of the wire
- on average the number of electrons entering wire = # exiting - thus net charge is zero
4
Q
current
A
traditionally defined as flowing positvie charges from higher voltage to lower voltage
5
Q
electric field
A
- region of space where a charged particle would feel an electrostatic force if it were placed there - referred to as a test charge (q’)
- test charges generally considered to be positive
- thus field moves away from positive charges and towards negative charges
- denoted as E
- units of N/coulomb
- vector quantity
6
Q
electric field equation
A
E=F/q’
electric force F acting on a test charge divded by the charge of the test charge
7
Q
electric field lines
A
point in direction of how a positive charge moves
- the closer the lines are the stronger the field is
8
Q
equipotential lines
A
- lines in electric field that a test charge would experience the same force and have the same potential to move
- connects all pts within an electric field sharing the same potential
- no work done by electric field if test charge moves position within same equipoential line
9
Q
when is work done a test charge by an electrical field?
A
- when the field has a tangent component to the equipotential surface
- equipotential lines and electric field lines are perpendicular
10
Q
what is the potential change when a test charge moves in the direction of a field line?
A
- the charge moves from higher potential to lower potential
11
Q
electrical potential energy
A
- increases when like charges are brought together and vice versa
- decrease when opposite charges are brought together and vice versa
- PEq=Kq1q2((1/rf))-(1/ri))
12
Q
electrical potential difference
A
- difference in electrical potential energy from starting position to ending position of a moving charge divided by the charge of the particle
- J/coulomb = a VoltP
- PEq=qV
- absolute potential is arrbitrary point assigned a zero voltage
13
Q
dielectric constant
A
- ratio of electrical forces between to charges when they are in a vacuum vs when they are in a medium
- increases with increasing polarity of the medium - the more interactions the medium can undergo, the more disruptive it can be to interacting charges
- Fmedium = Fvacuum/K where K is the dielectric constant of the medium
- F=Kq1q2/Kr2
14
Q
electric dipole
A
- P=qL
- occurs when two charges of opposite signs are separated from eachother by some distance L
- q is product of the charge
15
Q
magnetic field
A
- moving charged particle can create
- depends on speed of particle and magnitude of charge on particle
- can exert a force on any other charge moving through the field
- can be linear or radial depending on charge’s movement
- vector - magnitude and direction
- B (N*s/C*m) - Tesla = N/A*m - because one Ampere is C/s
- always form closed loops - move from north pole to south pole
