6.2 - Electric Fields

Question 1

What is an electric field?

Answer 1

A region of space in which charged particles are subject to an electrostatic force

Are due to charged particles

Question 2

How should electric field lines be drawn?

Answer 2

The direction of the electrostatic force on a positive charge (from positive to negative)

They should be perpendicular to the surface of the charged object

Lines that stretch from positive to negative show attraction whereas lines that do not join show repulsion

Question 3

How can uniformity charged spheres be modelled?

Answer 3

Point charges with their charge at a single point in the centre

They have radial fields around them

The strength of the radial field decreases as you get further away from the point charge

Question 4

What is electric field strength?

Answer 4

The force applied per unit charge on a positive test charge

Is a vector quantity (has direction and magnitude)

E = F/Q

Where:
•E = electric field strength, NC^-1 OR Vm^-1
• F = force, N
• Q = charge, C

Question 5

What is Coulomb’s law?

Answer 5

Any two point charges exert an electrostatic force between them that is proportional to the product of their charges and indirectly proportional to the square of their separations