Suspend a freshly pulled piece of transparent tape from the edge of your desk.

(a) What happens when you hold a battery near the tape? Does it matter whether you point the + side or the - side of the battery toward the tape? Does a spent battery yield a different result? Does a wooden object yield a different result? 

(b) What happens when you hold a strip of freshly pulled tape near the power cord of a lamp? Does it make any difference if the lamp is on or off?