All Flashcards
What is induced EMF?
Voltage generated by a changing magnetic field.
Define magnetic flux ().
The amount of magnetic field passing through an area; .
What is inductance (L)?
A measure of how much a coil resists changes in current, measured in henries (H).
Define the time constant (<math-inline>\tau) in an LR circuit.
The time it takes for the current in an LR circuit to reach approximately 63.2% of its maximum value; <math-inline>\tau = \frac{L}{R}.
What is the significance of Maxwell's Equations?
They tie together electricity and magnetism, explaining how electromagnetic waves propagate and are crucial for designing electrical devices.
What is Faraday's Law?
A changing magnetic field induces an electromotive force (EMF).
What is Lenz's Law?
The direction of the induced current opposes the change in magnetic flux that caused it.
What is the effect of increasing the number of turns in a coil on its inductance?
Increasing the number of turns increases the inductance.
What happens to the induced current if the rate of change of magnetic flux increases?
The induced current increases.
What is the effect of increasing the resistance in an LR circuit on the time constant?
Increasing the resistance decreases the time constant, causing the current to reach its maximum value more quickly.
What happens when a conductor moves through a magnetic field?
An electromotive force (EMF) is induced in the conductor.
What is the effect of a changing electric field?
A changing electric field creates a magnetic field (as described by Maxwell's Equations).
What is the key difference between Faraday's Law and Lenz's Law?
Faraday's Law: Quantifies the magnitude of induced EMF. | Lenz's Law: Determines the direction of the induced current.
Compare the behavior of current in an LR circuit immediately after a voltage is applied versus after a long time.
Immediately after: Current starts at zero and gradually increases due to the inductor's opposition. | After a long time: Current reaches its maximum value, limited only by the resistance.