Zusammenfassung der Ressource
Electric Fields and
potential
- Electric fields
- Attractive or repulsive
- Electric field strength
- The force per unit positive charge
- The force that a charge
of +1C would experience
- E = F/Q
- Field lines are drawn to show
the direction of the force that
would act on a +ve charge
- For parallel plates the lines point
from the most positive
plate/voltage to the least positive
- Radial Fields
- Any body that behaves
as if all its charge is
concentrated at the centre
- E = Q/(4piE0r^2)
- E is directly
proportional to 1/r^2
- on a graph of E against r the graph
starts at the surface/radius of the
sphere
- Uniform Fields
- E = V/d
- Coulomb's law
- F = (1Q1Q2)/(4PiE0r^2)
- F is -ve when the
charges are opposite and
the force is attractive
- F is +ve when the
charges are alike and
the force is repulsive
- F is proportional to 1/r^2
- Inverse square law
- Gives the force of attraction
or repulsion between two
point charges
- Electric Potential
- The work done per unit positive charge
on a positively test charge to move it
from infinity to that point in the field
- V = Q/(4piE0r)
- V is +ve when Q
is +ve and the
force is repulsive
- V is -ve when Q
is -ve and the
force is attractive
- Absolute Magnitude of
V is greatest on the
surface of the charge
- The gradient of a V
against r graph gives the
field strength at that point
- E = ▲V/▲r
- Electric Potential Difference
- ▲W = Q x ▲V
- The energy needed
to move a unit charge