Electric Force & Field Flashcards
How many types of charges are there? What are they?
Two; positive and negative
Fundamental charge
e of the electron
What does it mean by the fact that “Charge is quantized?”
The charge, q, on every object must be an integral multiple of the fundamental charge, e, of the electron.
Charge of 1C
1C = Charge of 6.242 * 10^18 e
What does the “Charge is conserved” mean?
The net charge of any isolated system is always conserved.
Three ways to transfer charge
Friction, Conduction, and Induction
Atoms consist of
A nucleus surrounded by an electron cloud.
What type of substance pulls electrons from another substance?
The more electronegative substance pulls electrons from the less electronegative substance.
Insulator
Charges immobile
Conductor
Charges mobile
Ground
Virtually limitless source or sink of charge.
Most natural material are…
lousy conductors, but also not very good insulators.
Polarization of molecule
Electron cloud distorted so that one end is positive and one end of the molecule is negative (forming a dipole).
Coulomb’s Constant
Ke = 1/4πepsilonnaught
Polarization of molecule
Electron cloud distorted so that one end is positive and one end of the molecule is negative (forming a dipole).
The principle of superposition of field
The resultant field at any point in space equals the vector sum of the fields created by the other present individual charges.
A mass m sitting in a g-field experiences a force that is equal to
F=mg(r)
g(r)
Measure of the strength of a gravitational field.
Test charge function
A test charge is used to probe the strength of an electric field generated by a charge q.
E(r)
Measure of the strength of an electric field.
E is produced by what?
The source charge q.
Electric Field Lines
Set of conventions that help visualize how E(r) permeates space (magnitude, direction)
All field lines begin where and end where?
All field lines begin at a positive charge and end at a negative charge.
E(r) is proportional to what?
The density of the field lines.
All field lines begin where and end where?
All field lines begin at a positive charge and end at a negative charge.
E(r) is proportional to what?
The density of the field lines.
E at any point is tangent to what?
Field lines.
Biased
Underestimate
Measures of Dispersion
Range, Standard Deviation, and Variance
Variance
Square of Standard Deviation.
z-score
Measure of relative standing. Number of standard deviations that a value is above or below the mean.
