6.2 Electric fields mastery sheet

Electric fields are due to

electric charges

Positive point charges emit field lines

radially outwards

Electric field lines point

perpendicular to the surface of the charge

Electric field lines show the direction

of force on an positive test charge

A uniformly charged sphere can be treated as

a point charge at its centre

Electric field strength

is the force experienced per unit positive charge

Electric field strength units are

NC^-1 or Vm^-1

Fields give rise to 

forces

Coulomb’s law is an example of

inverse square law

Fields due to multiple charges

superpose

Uniform field lines are

parallel and evenly spaced

To show a stronger field

space the lines more closely

Uniform fields can be produced by

parallel plate capacitors

Electric field strength in a capacitor is increased by increasing

the surface area overlap on the plates and/ or decreasing their separation

The capacitance of a parallel capacitor is..

inversely proportional to the separation of the plates

Units for the permittivity of free electrons entering a uniform electric field will..

move in a parabolic arc

electric potential is

zero at infinity

electric potential is

inversely proportional to its radial distance from a point source

electric potential is defined by

the work done in bringing a positive test charge from infinity to that point

Electric potential for a point source is

inversely proportional to r

electric potential of a charge is defined as

the electrical potential multiplied by the charge