A2 Physics-Electric and Magnetic Fields

Main subtitles are points from the specification. Notes are taken from a variety of textbooks. Not all information is strictly necessary; that that goes beyond the reach of the specification should still help with thinking about exam answers though

HideShow resource information

Pages in this set

Page 1

Preview of page 1
Unit 4-Physics On The Move
Topic 2-Electric and Magnetic Fields
Explain what is meant by an electric field and recognise and use
the expression for electric field strength E= Q

Charges and fields
Electric charge is one of the fundamental properties of nature. Two objects of the same charge…

Page 2

Preview of page 2
kQ1Q2 1
Use the expression F= r² where k= 4 and derive and use the
expression E= r² for the electric field due to a point charge
The electrostatic force between two charges spherical objects obeys an inverse square law: F= r²
, where Q and Q are…

Page 3

Preview of page 3
Any arrangement of two conductors isolated from one another by an insulator will form a capacitor.
In the lab this may be two sheets of metal with small pieces of plastic between. In this case air forms
the insulator. A commercial capacitor can be made by using sheets of…

Page 4

Preview of page 4
the wires). Surprisingly, the uncharged capacitor does not resist the current arriving at one plate or
leaving the other. On a graph of capacitor charge against time, the initial current is the gradient of the
graph at the origin. As charge build up on the plates, it repels more charge…

Page 5

Preview of page 5
Lines representing the magnetic field in a given region are called `lines of magnetic flux'. The number
of lines passing through a unit area perpendicular to the field represents the flux density, B, and is a
measure of the magnetic field strength.

The e.m.f. induced in a circuit can be…

Page 6

Preview of page 6
This is also the direction in which the magnetic force would act on a `free north pole' if
monopoles existed
In the case of the field round the long wire, the sense is determined by the direction of the
current in the wire

Force between two current-carrying wires
If the…

Page 7

Preview of page 7
of the torque changes, so the rotation is not smooth. The size of the torque on the coil can be
increased by

Increasing the area of the coil
Increasing the current in the coil
Using more turns of wire in the coil
Using a stronger magnetic field
Making the magnetic…

Page 8

Preview of page 8
is not at 90° to the magnetic field lines, then the angle between the path and the field lines must also
be taken into account.

Magnetically induced electric currents
The magnetic force on a moving charge can be used as a means of generating an electrical current.
Any piece of…

Page 9

Preview of page 9
bundled together or iron dust packed into the core. Very high-frequency transformers use cores
made from non-conducting but magnetic materials, such as ferrites. These materials are similar to
ceramics, and so can be quite brittle, and are far less easily magnetised than soft iron.
d(N )
Investigate, recognise and use…


Angat Singh


The owner of this resource is a true and utter miracle, honestly, I needed something just like this. My teachers are barely teaching anything during a lesson and are moving ridiculously slowly and the worst thing is they are doing it with poor detail. This resource really is amazing. Thank you so much! 

Similar Physics resources:

See all Physics resources »