715. If a digital multimeter set up to measure AC volts reads slightly above 'zero' when its leads are disconnected, what is this a result of?

A slight AC voltage reading with disconnected leads on a digital multimeter is likely due to electromagnetic interference inducing a small voltage, known as a ghost voltage. The meter's high input impedance makes it susceptible to picking up these tiny voltages from surrounding electrical fields, and this is a normal occurrence rather than an indication of miscalibration, grounding issues, or capacitor charge.