Electricity Flashcards
Electric field (E)
E = electrostatic force per unit charge
Strength of field at any point = potential
Analogous to gravity
Voltage (V)
V = energy per unit charge
V = potential for work by an electric field in moving any charge from one point to another
V = Ed
Analagous to gh
Difference b/w cathode and anode
Electric force
Attractive or repulsive
Exists b/w any two charges
Inversely proportional to square of distance b/w them
Acts through fields that exert given force per unit charge
Gravitational force
Always attractive
Exists b/w any two masses
Acts through fields that exert force per unit mass
Charges move from _____ to _____
Higher potential to lower potential (current)
Cathode to anode
Charge
Part of identity of subatomic partcles
Current runs in ____
Opposite direction of electrons
Units of charge (q)
Coulombs (C)
Coulomb’s Law
F = k((q1∗q2)/r^2 )
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k = Coulomb’s constant
(r = distance b/w centers of charge)
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Universal Law of Conservation of Charge
Universe has no net charge
Charge is quantized
Any charge must be at least as large as smallest possible unit
Similarities b/w gravity and electricity
Both mass and charge create fields
Both change inversely w/ square of distance b/w two centers
Field
Distortion of condition in space that creates force on charge/mass
Represented by lines of force
Lines of force
Point in direction of field (positive to negative for electric fields, towards mass for gravity)
Distance b/w lines = strength of fields
(Closer = stronger field)
Never intersect
Units of E
N/C or V/m
Force on a charge in an electric field
F = qE
Center of charge
Point from which charge is generated
Potential energy of charge in electric field
U = qEd
d = displacement
Units of voltage
Volts (V)
J/C
Conductors
Allow electrons to flow freely
Ex. metals