Why does an AC current cause a resonator to vibrate?
Answers
Answered by
0
The experiment is performed at very low temperatures to investigate the properties of superfluids. There's a circular resonator (made of aerogel) in a vertical magnetic field. An AC current gets passed through wires that are attached horizontally to the resonator. That causes it to move perpendicular to both the field and wires of course, because of the Lorentz force. The drive frequency gets changed to find resonance.
We measure the 'voltage in phase with the driving frequency'. When this is maximium, and the 'out of phase voltage' is minimum, that's a resonance. What exactly are these two quantities? What is it that's being measured when you measure 'in phase voltage'? Out of phase voltage should be zero but the lab manual says it'll never actually be zero and we have to set a zero point. Why? And what's meant by 'resistive background' to in phase voltage?
We measure the 'voltage in phase with the driving frequency'. When this is maximium, and the 'out of phase voltage' is minimum, that's a resonance. What exactly are these two quantities? What is it that's being measured when you measure 'in phase voltage'? Out of phase voltage should be zero but the lab manual says it'll never actually be zero and we have to set a zero point. Why? And what's meant by 'resistive background' to in phase voltage?
Similar questions