<What to prepare

Enameled wire wrapping (female cylinder)
Enameled wire
Beaker
Waterfowl
Vinyl string
Magnet
Conduit
galvanometer

＜1>

Wrap the enameled wire around the female cylinder. Remove the enamel by sanding both ends of the enameled wire with sandpaper.

＜2>

Attach a plastic string to the back of the waterfowl and attach a magnet to the end of the string. Attach the same number of magnets to the head of the waterfowl as you attached to the end of the string.

＜3>

Connect the coil made in <〈1〉 to the galvanometer with a conductor.

＜4>

Fill a beaker with water and wet the waterfowl's head.

＜5>

Place the magnet attached to the back of the waterfowl into the coil. Switch on the galvanometer and record the number displayed.