Lesson 9.1 focuses on Electromagnetic Induction and its applications.
General Physics 2 is related to Science, Technology, Engineering, and Mathematics (STEM).
Hans Christian Oersted's experiment: The initial investigation into the relationship between magnets and electricity.
Michael Faraday's further experiments (2 years later):
Sought ways in which a magnetic field can generate electric current.
Conducted experiments in the Thames River and at Waterloo Bridge to explore electricity induction from saltwater movement through Earth's magnetic field.
Foundational work for:
Magneto-hydrodynamic power generation: Converts fluid kinetic energy into electrical energy through electromagnetic induction.
Used in everyday technologies: Generators, transformers, and magnetic stripes in IDs and ATM cards.
Definition: Process where an electromotive force (emf) is generated in a conductor by changing the magnetic field around it.
Learning Competency: Identify factors influencing the magnitude and direction of induced emf and current, referring to Faraday’s Law.
Understand and explain electromagnetic induction.
Determine conditions necessary for inducing electromotive force and current.
Explore daily life applications of electromagnetic induction.
Mathematical Explanation:
A changing magnetic flux induces emf in a circuit.
Induction Experiments Overview:
Involves a solenoid and a magnet.
No current observed when the magnet is stationary.
Moving the magnet generates induced current (induced emf).
Zero current (B = 0): No magnetic field leads to no current.
Current flow (B increases): Current temporarily flows when the electromagnet is activated.
Current returns to zero: As magnetic field decreases.
Coil area change: Compressing/decompressing induced current.
Movement of solenoid: Induces current through motion within the magnetic field.
Turns in coil: Increasing/decreasing turns causes variation in induced current.
Turning off a magnet: Produces temporary current in the opposite direction.
Rate of action: Faster actions yield greater induced current.
Factors affecting emf: Geometry and magnetic fields influence induced current; composition of the material does not.
Changing Magnetic Flux (ΦB): Causes a change in magnetic field over time, directly related to induced emf.
Generators and Dynamos: Convert various energy types into electrical energy.
Generator Components:
Rotor: Coiling wires around metal cores.
Stator: Contains plates connected to the axle, works to induce current flow.
Electromotive Force (emf): Generated through the rotation of the shaft and coil.
Transformers: Allow long-distance electricity transmission; operate on the principle of induction.
Adjusts voltage and current based on the Law of Induction.
Uses coils of varying loops for magnetic flux transfer between coils.
Eddy Currents (Foucault's current): Induced electrical loops in response to changing magnetic fields.
Whirling motion of electrons occurs at right angles to the magnetic field.
Practical use in braking systems, such as train brakes.
Functionality: Store encoded information through magnetized layers.
Induction Mechanism: Swiping a card changes magnetic flux, inducing an emf in the reader.
Relevant across many devices: Generators, transformers, eddy currents, and magnetic card stripes.
Mastery of electromagnetic induction principles essential for understanding various technological applications.