1. Magnetic field: the distribution of a magnetic force in the region of a magnet à 2 different magnetic characteristics, labelled north and south ß responsible for magnetic forces.
2. North + North and South + South, repel each other
North + South, attract each other.
North + South, attract each other.
3. Magnets also attract certain metals, such as iron, nickel and cobalt ß these are called ferromagnetic metals.
4. Domain Theory: All large magnets are made up of many smaller and rotatable magnets ß dipoles. Dipoles can interact with other ones close by. If the dipoles line up, then a small magnetic domain is produced.
5. Oersted’s principle: charge moving through a conductor produces a circular magnetic field around the conductor.
6. Mapping the magnetic field allows you to predict the direction of the electromagnetic force from the current.
7. Right-hand rule allow you to take certain known factors and predict one unknown factor. There are three right-hand rules.
8. Right-hand rule #1 (RHR#1) for conventional current flow: grasp the conductor with the thumb of the right hand pointing in the direction of conventional, or positive (+), current flow. The curved fingers point in the direction of the magnetic field around the conductor.
9. Rule #1 allows you to turn the magnet on and off ß current flow through the conductor is interrupted.
10. Rule #2: coiling the wire in a linear cylinder straightens out the field
11. Right-hand rule #2 (RHR#2) for conventional current flow: grasp the coiled conductor with the right hand such that curved finger point in the direction of conventional, or positive (+), current flow. The thumb points in the directs of the magnetic field within the coil. Outside the coil, the thumb represents the north (N) end of the electromagnet produced by the coil.
12. Formula comparison of strength of magnetic fields (B).
Current in the coil:
B1=B2(I2/I1)
Number of turns in the coil:
B1=B2(n2/n1)
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