Question

1. a bar magnet has been cut into four pieces of equal length and width. what is the pole strength of each piece compared to the pole strength of the original bar magnet?

a. double, because the magnetic domain only depends on the width of the magnet
b. equal, because the magnetic domain is independent of the width and length of the magnet
c. one - half, because the magnetic domain only depends on the length of the magnet
d. one - fourth, because the magnetic domain depends on the length and width of the magnet

Explanation:

Pole strength of a magnet is related to the cross-sectional area (tied to width here, as length is the axial dimension). When cut into 4 equal pieces of equal length and width, each piece has half the original width and half the original length. The pole strength is proportional to the cross-sectional area; if width is halved, cross-sectional area is halved, so pole strength becomes one-half of the original. Option C correctly states this, linking pole strength to the magnet's length (axial cut reduces the effective cross-sectional contribution tied to pole strength).

Answer:

C. one-half, because the magnetic domain only depends on the length of the magnet