1 0 / 5 / 2 0 2 3 2
4. Electromagnetic Induction
5. Electric Current
6. Electric Power
+ Magnetism is a force that causes certain materials to attracts or repel
+ This force is caused by the motion of electrons within atoms.
+ When electrons spin in the same direction,they create a magnetic
4. + There are three types of magnets;
+ Naturally occurring magnets,
+ Artificially induced permanent magnets,
5. + Many materials are unaffected when brought into a magnetic field. Such materials
are nonmagnetic and include substances such as wood and glass.
+ Diamagnetic: Weakly repelled
e.g. Water and Plastic.
+ Ferromagnetic: Strongly attracted by a magnet
e.g. Iron, cobalt, and nickel.
+ Paramagnetic: Lie somewhere between ferromagnetic and nonmagnetic
e.g. Contrast agents used in MRI are paramagnetic
6. + An Electromagnet is a magnet that is created by the flow of electric current through
+ The strength of the magnetic field can be controlled by varying the amount of current
flowing through the wire.
+ Electromagnets are used in a wide range of applications, from electric motors
to MRI machines.
+ A moving charge creates a magnetic field called electromagnetism.
7. + Magnetic induction is the process of creating a magnetic field in a material by placing
it in a magnetic field.
+ When a magnetic material is placed in a magnetic field, the electrons in the material
align themselves with the magnetic field, creating a net magnetic field.
+ This process is used in the construction of transformers and electric generators.
8. + Electric current is the flow of electric charge in a circuit.
+ Measured in Ampere (A)
+ Ohm’s law
+ Ohm’s law states that the current flowing through a conductor is directly proportional to voltage across
it, and inversely proportional to its resistance.
I = V/R
9. + Electric power is the rate at which electrical energy is transferred or consumed in a
+ Measures in Watts (W)
+ Represented by “P”
V = voltage
I = current
P = VI