Does the B strip you created in Checkpoint 22.8 carry a positive charge or a negative charge?

Checkpoint 22.8

Prepare one charged strip of tape according to Figure 22.3 and hang it from the edge of your desk. Hang a narrow strip of paper from the desk edge also, about \(0.5 \mathrm{~m}\) away from the tape strip. Pass a plastic comb six times quickly through your hair and then show that the comb is charged. Be sure to use a plastic comb; combs made from other materials do not acquire a charge when passed through hair. The cheapest type of comb usually works best.

Make a pair of oppositely charged B and T strips (Figure 22.5) and investigate how they interact with a charged comb.

Does your comb behave like a B strip, a T strip, or neither?

Figure 22.3 Procedure for making strips of transparent tape that interact electrically. The purpose of the foundation strip is simply to provide a standard surface. On flat surface, stick down tape strip as foundation: flatten with thumb. Fold end of second strip to make handle; smooth onto foundation strip. 3 Pull second strip off in one quick motion. Holding both ends of strip to prevent curling, hang strip on table edge. foundation strip