An RLC series circuit is powered by a sinusoidal voltage source of variable frequency vE(t)=VEcos(2πft). The current i(t)is the same throughout the circuit. It is, like the entry voltage, sinusoidal but its amplitude and phase depend on the frequency: i(t)=Icos(2πft+φ)
The voltage vR(t) observed on the oscilloscope is a reflection of the current. (vR(t)=Ri(t)). The amplitude reaches a maximum for a certain frequency, called the resonance frequency f0. It depends only on L and C.
Click and drag the slider to change the values of R, L, C and f.
Click on “cursors” to make measurements of phase differences.