Electric and magnetic fields, OCR- Unit 5, module 1

Electric and magnetic fields, OCR- Unit 5, module 1

HideShow resource information
  • Created by: Sameer
  • Created on: 13-05-12 18:37
Preview of Electric and magnetic fields, OCR- Unit 5, module 1

First 368 words of the document:

Physics Unit 5, module 1
Sameer Jahabarali Physics
Electric fields are created electric charges, in which the field strengths represent the
force experienced per unit positive charge. Electric field lines represent:
Direction of force, through the arrows represented (positive repels if a
charge which is relatively more negative, which will is attract)
Strength, which is represented by the gap between each field lines, where
closer the lines stronger the force
There are two types of electric fields:
Uniform fields; occur between charged parallel plates. Charged plates can be
created in a circuit, where E V. As the distance
between the charge plates increase, the strength of
the electric field decreases, hence E 1/d. joining
these two proportionalities together we get the
formula for uniform electric field strength.
Radial fields, occur in a point charges. Similar to
gravitational field strength, E 1/r2. Furthermore, E Q and one final factor that affect
E is the medium (e.g. medium can have and vary charge, like water) knowing this E
1/. Joining all these probabilities gives us the formula of radial electric field strength.
The force these electric fields exert on another charged particle is given by
multiplying the electric field strength by the charge of the new particle or plate.
This is because F=EQ (derived from E=F/Q). Coulomb's law is the Force experience
between two point charges (radial electric force).
In a uniform electric field, the motion of a charged particle will:
Gravitational fields Electric Fields
Attractive force only Attractive and repulsive
E 1/r2 E 1/r2
mass induces a Charge induces a force
force
Vector vector
Accelerate vertically in direction of force acting on the particle (i.e. if particle is positive accelerate
towards the negative and vice versa). The acceleration is the force in a uniform electric field (where Q
is the particle), divided by mass (F=MA)
Travel at a constant horizontal velocity. The velocity is to be calculated before or given.
The similarites and difference between gravitational and electric fields.

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Physics Unit 5, module 1
Sameer Jahabarali Physics
Magnetic fields
Magnetic field is a region where particles with magnetic properties and moving, charged particles with
experience a force.
A magnetic field is induced by two types of magnets:
Permanent magnets- magnets with North and South pole that has a
magnetic field around it that couldn't be "turned off"
Electromagnets (temporary)- magnets that produce a magnetic field by the
flow of current. This can be "turned off" if current flow is stopped.…read more

Page 3

Preview of page 3

Here's a taster:

Physics Unit 5, module 1
Sameer Jahabarali Physics
Knowing that a current flow can induce a magnetic field, it is also possible to induce an emf (electron motive
force- voltage (energy make current (electron) flow)).…read more

Page 4

Preview of page 4

Here's a taster:

Physics Unit 5, module 1
Sameer Jahabarali Physics
AC generator is used to supply electricity as it is more efficient, because resistance can be reduced by
transforming electricity by:
Step- up- number of turns of secondary coil is greater than primary. This increases voltage,
decreases current (conservation of energy)
Step-down- number of turns on primary is greater
than secondary. This decreasing voltage, increase
current
In order to transform a.c electricity, a transformer is used.…read more

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all resources »