Physics 22.2 Electric Field Strength

Question 1

What is electric field strength?

Answer 1

The electric field strength at a point in the field is defined as the force per unit charge on a positive test charge placed at that point.

Question 2

What type of quantity is electric field strength?

Answer 2

Electric field strength is a vector quantity. By convention, it points in the direction that a positive charge placed at that point in the field would feel a force.

Question 3

What is the equation for electric field strength in a uniform field?

Answer 3

E=V/d

E is the electric field strength in volts per metre [V m^-1]
V is the potential difference between the plates in volts [V]
d is the distance between the plates in metres [m]

Question 4

What happens when a charged particle enters an electric field at right angles to the field?

Answer 4

If a charged particle enters an electric field at right angles to the field, it will feel a constant force parallel to the electric field lines. This causes the particle to accelerate at right angles to its original motion, and hence it follows a curved path (a parabola)