What is Electromagnetic Induction?
Using magnetic fields to create voltage. A changing magnetic field induces a voltage (EMF) in a conductor. If the circuit is closed, this EMF drives a current.
What is magnetic flux ($\Phi_B$)?
The amount of magnetic field passing through a given area. Quantified by the formula: $\Phi_B = B * A * cos(\theta)$ where B is the magnetic field strength, A is the area, and ฮธ is the angle between the magnetic field and the area vector.
Define Faraday's Law.
The induced EMF in any closed circuit is equal to the negative of the time rate of change of the magnetic flux through the circuit: $\varepsilon = -N \frac{d\Phi_B}{dt}$ where N is the number of turns in the coil.
What is Lenz's Law?
The direction of the induced EMF (and thus the induced current) will always oppose the change in magnetic flux that caused it.
Define EMF.
Electromotive Force: The voltage generated by a changing magnetic field, which can drive a current in a closed circuit.
What are the steps to determine the direction of induced current using Lenz's Law?
1. Determine the direction of the original magnetic field. 2. Determine if the magnetic flux is increasing or decreasing. 3. Determine the direction of the induced magnetic field (it opposes the change in flux). 4. Use the Right-Hand Rule to find the direction of the induced current from the induced magnetic field.
How can magnetic flux be changed?
1. Changing the magnetic field strength (B). 2. Changing the area (A) of the loop. 3. Changing the angle (ฮธ) between the field and the area.
What is the effect of increasing the number of loops (N) in a coil, according to Faraday's Law?
The induced EMF ($\varepsilon$) increases proportionally: $\varepsilon = -N \frac{d\Phi_B}{dt}$.
What happens if a magnet is moved towards a coil of wire?
The changing magnetic flux induces an EMF in the coil, causing an induced current to flow. The direction of this current creates a magnetic field that opposes the motion of the magnet.
What is the effect of increasing the speed at which a magnet moves relative to a coil?
The rate of change of magnetic flux increases, resulting in a larger induced EMF and, consequently, a larger induced current.
What happens when a conducting loop is moved parallel to a uniform magnetic field?
There is no change in magnetic flux through the loop, so no EMF is induced, and no current flows.
What is the effect of increasing the magnetic field strength (B) on the induced EMF?
A stronger magnetic field leads to a greater magnetic flux and, if the flux is changing, a larger induced EMF.
