1. PHY 2049: Physics II
Tutoring Center is open in room NPB 1215, M-F 12:00AM -4:00PM. It is free.

2. Ch. 30 Induction and Inductance
Magnetic Flux
Faraday’s Law of Induction
Lenz’ law
Inductors
Self and Mutual
Series RL circuits
Magnetic Energy

3.     
PHY 2049: Physics II

4. PHY 2049: Physics II When the switch is first thrown
    
PHY 2049: Physics II
When the switch is first thrown
The inductors block any current. All current flows through the middle resistance. I = V/R
Later, the inductors are all closed and the current is then I = 3V/R.
How much time does it take for the current to rise?

5. On R-L circuits
When the switch S in the circuit shown is closed, the time constant for the growth of current in R2 is:
V = L dI/dt +IR2

6. 4 1 2 3
hitt
The four wire loops shown have edge lengths of either L, 2L, or 3L. They will move with the same speed into a region of uniform magnetic field B, directed out of the page. Rank them according to the maximum magnitude of the induced emf, least to greatest.
A. 1 and 2 tie, then 3 and 4 tie B. 3 and 4 tie, then 1 and 2 tie C. 4, 2, 3, 1 D. 1, then 2 and 3 tie, then 4 E. 1, 2, 3, 4

7. Electromagnetic Osciallations and Alternating Current
Current changes expo in an R-L circuit
Charge changes expo in an R-C circuit
Sinusoidal in and L-C circuit
Analogous to a harmonic Oscilaltor

9. The Potentials
Charge up a capacitor, plug in an inductor and unplug battery.
Pot across inductor oscillates.
The potential across a capacitor oscillates.

10. Alternating Currents
A resistance

11. Alternating Currents
The current leads the voltage

12. Inductor
The current lags the voltage