## PHYS208 Fundamentals of Physics II

### Hint for Ch. 33, 43E

Eavluate the resonant frequency and use the appropriate formulas for X_{L}.

### Hint for Ch. 33, 47E

a) - b)
Set the arguments of the sine function for emf and current to *pi*/2 to find the maximum
value.

c) Does the current lead or lag the emf? or is it in phase?

d) The ratio of the emf magnitude to the current magnitude is the impedance of the circuit.
Use the appropriate formula for the contribution to the impedance for the circuit
element determined in part c).

### Hint for Ch. 33, 49E

a) Follow the sample problem, but carry out the evaluations using X_{C} = 0.

b) Find a ruler and some graph paper! Keep in mind that the voltage phasor diagram is often
shown at an arbitrary angle, but it is convenient to consider the time at which the resistive
voltage phasor is along the positive *x*-axis.

### Hint for Ch. 33, 51E

a) Follow the sample problem, but carry out the evaluations using X_{C} = 37.9 ohm.

b) Find a ruler and some graph paper! Keep in mind that the voltage phasor diagram is often
shown at an arbitrary angle, but it is convenient to consider the time at which the resistive
voltage phasor is along the positive *x*-axis.

"http://www.physics.udel.edu/~watson/phys208/exercises/hints/0506.html"

Last updated May 7, 1998.

Copyright George Watson, Univ. of Delaware, 1997.