THE PRACTICE STUDIO

Go slowly. Ask why. Make it yours.

PRACTICE · MEMBERSAdvanced · Single correct

PRACTICE / Electrical resonance

Reconstruct a capacitor from the response curve

A fixed 4.0 V peak sinusoidal source drives a series RLC circuit. The peak of the current-amplitude curve is 0.25 A. The two half-power angular frequencies are 300 and 500 rad/s.

What capacitance follows from the constant-element series model?

Organize the givens & assumptions
  • Source amplitude: 4.0 V peak
  • Maximum current amplitude: 0.25 A
  • Half-power angular frequencies: 300 and 500 rad/s

Steady sinusoidal response; total series R, L and C are positive and frequency independent; source amplitude is constant. Half-power refers to resistor heating, not half current amplitude.

  1. A50 μF50\ \mu\mathrm F
  2. B2503 μF\frac{250}{3}\ \mu\mathrm F
  3. C125 μF125\ \mu\mathrm F
  4. D250 μF250\ \mu\mathrm F

Try it on paper first. Free sample problems in every collection include the complete reasoning: find one in this collection →