Defining the magnitude of the Magnetic Field
Look again at the experiment on interaction between magnet and current :
animation
Study the theory here:
lesson
Small recap
The acceleration of gravity on the surface of the earth is defined by dividing the weight force by the mass:
The electric field E is defined by dividing the Coulomb’s force by the testing charge q:
What about the magnetic field?
we can measure the force on a current carrying wire inside a magnetic field
we find that this force i proportional to the intensity of the current
we find that the force is proportional to the lenght of the electric wire immersed in the magnetic field.
we find that the force changes changing the magnet generating the magnetic field.
Our aim is to thefine the intensity of the magnetic field. We are looking for a quantity that depends only by the field (e.g. by the magnet)
So, this quantity can be found dividing the force by the intensity of current and the lenght of the wire.
This gives us a way to determine the intensity of magnetic field, measuring the current and the force.
Write down the answer to the following questions about force on a current carriying wire in a magnetic field:
- The force is proportional to ...
- How is defined the ’magnetic field strength’ B, and why?
- What are the units of the magnitude of magnetic flux density B?
Homeworks
for monday 29th-02-2016
the itc lab is out of order. it would be useful if you
Bring Your Own Device (as tablet, laptop, etc.)
Did you write the above questions with the relative ansuers during the last lesson on your notebook?
If not, do it now.
Summarize all the concepts studied on the magnetic field in the last lessons in one mind map
And do the poll