PHYS208 Fundamentals of Physics II

Answer for Ch. 33, 55P

The resonant frequency of the circuit is 1000 rad/s. Thus the inductive reactance is 1000 ohm. However at resonance the impedance of the circuit is just the resistance 10 ohm, with a resulting current at resonance of (10 V)/(10 ohm) = 1.0 A. The resulting voltage across the inductor (and capacitor, pi out of phase) is (1.0 A)(1000 ohm) = 1000 V!

Answer for Ch. 33, 56P

The inductive reactance is 514 ohm and the capacitive reactance is 182 ohm. Thus the net reactance is 332 ohm; the resistance must be 89 ohm for the phase angle to be 75 degrees.

Answer for Ch. 33, 58P

a) 16.6 ohm

b) 422 ohm

c) 521 mA

d) capacitive reactance increases

e) 408 ohm, which is less than before

f) current increases

Answer for Ch. 33, 61P

a) 707 ohm

b) 32.2 mH

c) 0.022 microF

Answer for Ch. 33, 63P

a) The inductive and capacitive reactances are not equal.

b) 15.6 microF

c) 255 mA

Last updated May 7, 1998.
Copyright George Watson, Univ. of Delaware, 1998.