Electric Fields Flashcards
What is an electric field?
The region around a body in which other charged bodies will feel a force due to the electric charge of the body.
What do electric field lines show?
The shapes of the field and the direction of the field in which a small positive charge would move at that point.
What is electric field strength?
The force per unit positive charge in newtons per coulomb.
In which direction would the field lines point from a positively charged sphere?
Away from the sphere.
What does Coulomb’s law state?
The electrical force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of their separation.
What is the permittivity of free space?
A physical constant related to the size of the force between electric charges in free space.
What equation is used for uniform electric fields?
E = V/d
What is permittivity?
A constant related to the size of the capacitance of a capacitor.
What is the relative permittivity of a material?
The factor by which the capacitance of a capacitor with that material between its plates is increased relative to the capacitance if a capacitor with air or vacuum between its plates.
What equations can be used to describe the motion of a particle between two uniform plates in the vertical and horizontal directions?
Horizontal: linear motion e.g. v = s/t
Vertical: constant acceleration e.g. suvat, F=ma
What is electric potential?
The work done per unit positive charge to move that charge from infinity to a point in an electric field.
What is electric potential energy?
The work done to move that charge from infinity to a point in an electric field.
