PHYS208 Fundamentals of Physics II

Answer for Ch. 33, 25P

a) Utot = 1.98 microJ

b) qmax = 5.56 microC

c) imax = 12.6 mA

d) phase angle is -46.9 degrees

Why negative? We found that the cosine of the phase angle should be 0.68; thus the phase angle may be +/- 46.9 degrees. The sign is chosen depending on whether the capacitor is charging or discharging. To decide, look at the time derivative of the charge at t=0, which is proportional to the negative of the sine of the phase angle. For a charging capacitor, this derivative should be positive; thus the choice of -46.9 degrees.

e) phase angle is +46.9 degrees

Last updated Nov. 25, 1997.
Copyright George Watson, Univ. of Delaware, 1997.