I am sure most of you out there have done the experiment with a flashlight and solar cell with a audio source . I have some students that want the "ideal" inductor in phase with the flashlight. After solving for the inductance of a 3volt flashlight-bulb solenoid combination what is the ideal situation? A greater induced audio source, or less? Is it the back emf that the audio source "gets phased" with ? Any suggestions welcome.