M6C2

Question 1

Define electric field

Answer 1

The region around a body in which other charged bodies will feel a force due to the electric charge of the body

Question 2

What do electric field lines show on an illustration of an electric field

Answer 2

They show the shape and strength of the electric field and the direction that a small positive charge particle would move in the field

Question 3

What’s meant bu electric field strength?

Answer 3

The force per unit charge. Units are newtons per coulomb (N C^-1). It’s the force that a charge of +1C would experience while at this point in the field

Question 4

When two nearby positive charges interfere with each other what is produced

Answer 4

A neutral spot will be produced where there is no magnetic field

Question 5

In a large metal sphere what effect does the charge be concentrated in the centre ,instead of the edge of the sphere, have on the magnetic field?

Answer 5

None, there is no field produced inside the sphere. The outside field is the same whether the charge is centred in the centre or the edge.

Question 6

What happens when electrodes are made to have a sharp point on one end?

Answer 6

Strong electric fields are produced in small volumes concentrated around the point.

Question 7

What is Coulomb’s law?

Answer 7

The electric force between two point charges is directly proportional to the product of the charges and the inverse of the square of the distance between them. F ∝ Qq/r^2

Question 8

What is meant by permittivity of free space (𝜀o)?

Answer 8

The physical constant related to the size of the force between electric charges in a vacuum (free space). It ha s a value of 8.85x10^-12 C^2 m^-2 N^-1

Question 9

What is the equation gotten from Coulomb’s law?

Answer 9

F = Qq / 4𝜋𝜀or^2
F = force (N)
Q,q = charge (C)
𝜀o = permittivity of free space (8.85x10^-12 C^2 m^-2 N^-1)
r = distance between the charges (m)

Question 10

What is the electric field strength equation?

Answer 10

E = F/Q
E = Electric field strength (N C^-1)
F = Force (N)
Q = Charge (C)

Question 11

What equation can we derive from Coulomb’s law?

Answer 11

E = F / Q
F = Qq / 4𝜋𝜀or^2
F / q = Q / 4𝜋𝜀or^2
E = Q / 4𝜋𝜀or^2
E = Electric field strength (N C^-1)
Q,q = charge (C)
𝜀o = permittivity of free space (8.85x10^-12 C^2 m^-2 N^-1)
r = distance between the charges (m)