Chapter 30

Inductance, Electromagnetic Oscillations, and AC Circuits

Our approach

• Mutual induction

• Self-inductance

• Energy in a B-field

• LR circuits

• LC circuits

• LCR series circuit

• Resonance in an LCR circuit

Mutual Inductance

• In what general situations does mutual inductance occur? (Sketch it out)

• The quantity Mutual Inductance, M21, can be considered a proportionality constant between what two quantities?

• How are the emfs related to mutual inductance in each circuit derived, and what are they?

• What maximizes mutual inductance?

Self-Inductance

• In what general situation does self-inductance occur? (Sketch it out)

• The self-inductance, L, can be considered a proportionality constant between what two quantities?

• How is the emf in the circuit related to self-inductance derived, and what is it?

• What is the circuit diagram symbol for self-inductance?

Self-Inductance (cont’d)

• How is the self-inductance figured out for a few simple cases?

Energy in a B-field

• What is the work done to increase the current from zero to I in an inductor with inductance L? Why does this make sense?

• What is the energy density in a magnetic field? Why does this make sense?

LR Circuits

• What is a simple LR circuit?

• What equation governs its behavior?

• What is its behavior (in words, graphs, mathematically)?

• If L is analogous to mass, what physical situation is analogous to an LR circuit?

LC Circuits

• What is a simple LC circuit?

• What equation governs its behavior?

• What is its behavior (in words, graphs, mathematically)?

• If L is analogous to mass, what physical situation is analogous to an LC circuit?

LCR Circuit

• What is a simple LCR circuit?

• What equation governs its behavior?

• What is its behavior (in words, graphs, mathematically)?

• If L is analogous to mass, what physical situation is analogous to an LCR circuit?

Resonance in an LCR Circuit

• In what way can resonance occur in an LCR circuit?

• How is this resonance analogous to resonance of a damped, driven harmonic oscillator?

the end