1) Refer to the capacitor slide from the lectures, copied below. Suppose we have a condenser microphone composed of two parallel plates, one of which can move closer to or farther away from the other in response to a sound wave. Let the capacitance when no sound is present be 1x10-10 Farad. Now charge the plates to 24 volts and arrange for the charge to remain constant (another circuit does this for us). If the capacitor has a plate area of 1x10-4 square meters, how far does the moving plate have to move in order for the capacitor voltage to change by +1 volt? How about -1 volt? (You'll need the "physical constant", i.e., the permittivity: & = 8.85x10-12 Farad/ meter). Electric charge Q (coulombs) +++ Capacitors Voltage between plates V (volts) Q = CV physical constant A Plate area A, spacing d Capacitance C = & (sq. meters) (meters) (farads)