22 : Electric fields Flashcards
define electric field strength
force experienced per unit positive charge at the point
field produced by positive point charge
- a repulsive field
- direction of field away from object
- repels positive charge
field produced by negative point charge
- a attractive field
- direction of field towards the object
attracts positive charge
define electric potential
work done per unit charge in bringing positive charge from infinity to that point
define electric potential difference
work done per unit charge between two points around the particle of charge
effect of distance on electrostatic force
the greater the distance the weaker the force
what is coulomb’s law
the force between any two point charges is proportional to the product of their charges and inversly proportional to teh square of the distance between them.
permittivity
the ability of a material to transmit an electric field
formula for potential at a point in a field
V = W/Q
motion of charged particles in a electric field
- projectile motion
- two components of motion are independent
- velocity perpendicular is not affected
calculate velocity parallel to plate
- time = length of charged plate / perpendicular speed
- acceleration = Eq/m
= v = u+at
formula for electric potential energy near a point charge
E = vq