A student set up an experiment to determine the magnetic flux density between two
magnadur magnets. A magnadur magnet has its north and south poles on opposite large
rectangular faces. The two magnets were attached to a yoke, with opposite poles facing,
as shown in the diagram.
The student zeroed the balance and then placed the magnets and yoke on it. The reading
A conducting rod connected to a d.c. power supply was held stationary between the
magnets as shown. An ammeter was used to measure the current through the conducting
The circuit diagram shows the arrangement when viewed from above.
The power supply was switched on. The student increased the current through the
conducting rod and the corresponding reading on the balance was recorded.
The following results were obtained.