Electric Fields Flashcards
What does the direction of the field show?
the direction of force experienced by a small positive charge placed at a point
What is indicated by the separation between the field lines?
electric field strength
What is a uniform field made up of?
2 oppositely charged parallel plates
What are electric field lines always perpendicular to?
the surface of the conductor
What are radial field lines like?
straight field lines converging to a point at the centre of the charged object
What happens to field strength as the distance from the object increases?
gets smaller
How do you calculate electric field strength?
(force experienced by positive charge)/(positive charge)
What is Coulombs law?
two point charges exert an electrostatic force on each other that is directly proportional to the product of their charges and inversely proportional to the square of the distance between them
What happens to electric field strength and radius within radial fields?
E obeys the inverse square law with r
What are the similarities between gravitational and electric fields?
- field strengths both obey inverse square law with distance
- both produce a radial field pattern
What are the differences between gravitational and electric fields?
- gravitational depends on mass but electric on charge
- gravitational always produce attractive but electric can be attractive or repulsive
What direction of force will a particle of positive charge Q+ experience in a uniform electric field?
in the direction of the field
What happens to a particle of positive charge Q+ in. uniform electric field?
particle moves from positive to negative
How do you calculate the work done of a positively charged particle in a uniform electric field?
VQ
When does a particle accelerate in a uniform electric field?
when a positive charge moves in the direction of the field
When does a particle decelerate in a uniform electric field?
when a negative charge moves in the direction of the field
What happens when the motion of a particle is perpendicular to the field in a uniform electric field?
parabolic path when initial velocity is perpendicular to the direction of the field
What remains constant when the motion of a particle is perpendicular to the field in a uniform electric field?
velocity
What must be done to bring like charged particles together?
external work
What is the area under a force separation graph equal to?
work done on the charged particles
Define electric potential enegry:
work done on the charged particles from infinity to separation r
When and why is electric field strength negative sometimes?
2 particles with unlike charges as external work must be done
When does electric potential energy equal 0?
at infinity
