Topic 7: Electric & Magnetic Fields
0.7 Specification notice:
In order to develop their practical skills, students should be encouraged
to carry out a range of practical experiments related to this topic. Possible
experiments include using a coulomb meter to measure charge stored
and using an electronic balance to measure the force between two
charges.
Mathematical skills that could be developed in this topic include
sketching relationships which are modelled by y = k/x, and y = k/x2, using
logarithmic plots to test exponential and power law variations,
interpreting logarithmic plots and sketching relationships that are
modelled by y = e-x.
This topic may be studied using applications that relate to fields, for
example, communications and display techniques.
7.Q Exam questions
,7.108 Understand that an electric field (force field) is defined
as a region where a charged particle experiences a force
Define Electric Field? A region of space in which a charged
particle experiences a force
What are the 2 types of electric fields? ● Radial fields:
● Uniform fields:
This is approximately what it looks like at
the Earth’s surface
7.109 understand that electric field strength is defined as
E=F/Q and be able to use this equation
Define Electric Field Strength and what are ● The force per unit positive charge
its 2 units and its equation? (thus, its direction is the direction a
positive charge would move)
● NC-1 or Vm-1
● E=F/Q
If the charge given is negative and thus the
field strength too then the field points are
going in the opposite direction
, 𝑄1 𝑄2
7.110 be able to use the equation 𝐹 = , for the force
4𝜋𝜖0 𝑟 2
between two charges
What is permittivity? 𝜖0 ● How difficult it is to generate an
electric field in a medium
● The higher the permittivity of a
material, the more charge is needed
to generate an electric field of a
given size
What is Coulomb’s law and the quantities The force on a charged particle is directly
that are proportional to each other? proportional to the product of the two
charges and inversely proportional to the
distance of separation squared
(Force between two point charges where
attractive is negative and repulsive is
positive).
Air can be treated as a vacuum thus use ε0
𝑄
7.111 be able to use the equation 𝐹 = for the electric
4𝜋𝜖0 𝑟 2
field due to a point charge
What are the 3 Coulomb’s law equation
variants for an electric field due to a point
charge?
Then E=F/Q
0.7 Specification notice:
In order to develop their practical skills, students should be encouraged
to carry out a range of practical experiments related to this topic. Possible
experiments include using a coulomb meter to measure charge stored
and using an electronic balance to measure the force between two
charges.
Mathematical skills that could be developed in this topic include
sketching relationships which are modelled by y = k/x, and y = k/x2, using
logarithmic plots to test exponential and power law variations,
interpreting logarithmic plots and sketching relationships that are
modelled by y = e-x.
This topic may be studied using applications that relate to fields, for
example, communications and display techniques.
7.Q Exam questions
,7.108 Understand that an electric field (force field) is defined
as a region where a charged particle experiences a force
Define Electric Field? A region of space in which a charged
particle experiences a force
What are the 2 types of electric fields? ● Radial fields:
● Uniform fields:
This is approximately what it looks like at
the Earth’s surface
7.109 understand that electric field strength is defined as
E=F/Q and be able to use this equation
Define Electric Field Strength and what are ● The force per unit positive charge
its 2 units and its equation? (thus, its direction is the direction a
positive charge would move)
● NC-1 or Vm-1
● E=F/Q
If the charge given is negative and thus the
field strength too then the field points are
going in the opposite direction
, 𝑄1 𝑄2
7.110 be able to use the equation 𝐹 = , for the force
4𝜋𝜖0 𝑟 2
between two charges
What is permittivity? 𝜖0 ● How difficult it is to generate an
electric field in a medium
● The higher the permittivity of a
material, the more charge is needed
to generate an electric field of a
given size
What is Coulomb’s law and the quantities The force on a charged particle is directly
that are proportional to each other? proportional to the product of the two
charges and inversely proportional to the
distance of separation squared
(Force between two point charges where
attractive is negative and repulsive is
positive).
Air can be treated as a vacuum thus use ε0
𝑄
7.111 be able to use the equation 𝐹 = for the electric
4𝜋𝜖0 𝑟 2
field due to a point charge
What are the 3 Coulomb’s law equation
variants for an electric field due to a point
charge?
Then E=F/Q
