Electric Fields Flashcards
1
Q
Rules for electric field lines
A
- Positive charge to negative charge
- Electric field lines are always right angles to the surface
- Uniform fields are equally spaced and parallel
- The closer the electric field lines the greater the electric field strength
2
Q
Coulomb’s law
A
The electrostatic force experienced by 2 points charges on each other is directly proportional to the product of their charges and inversely proportional to the square if their separation
3
Q
Define electric potential energy
A
The work done to move a point charge from infinity to a point in the field
4
Q
Define electric field strength
A
Force per unit positive charge
5
Q
What is the area under a force distance graph
A
Work done
6
Q
Similarities between electric fields and gravitational fields
A
- Forces for both inversely proportional to separation squared
- Both radial fields
- Field strength are both per unit mass or charge
- Gravitational or electric potential is always zero per unit mass or per unit charge when at infinity
7
Q
Difference between electric fields and gravitational fields
A
- Gravitational forces are always attractive, electric forces are either attractive or repulsive
- Objects can be shielded from electric fields but not gravitational fields
- The size of the electric force depends on the medium between charges. For gravitational forces it makes no difference
8
Q
Derive c=4πε₀R
A
C=Q/V
Q=4πε₀r²v
V cancel
