An experiment is set up to measure magnetic flux density using a digital balance. Two magnets are placed on a yoke on the balance, producing a uniform horizontal magnetic field between them. A horizontal copper wire of length L=6.20 cmL = 6.20\text{ cm}L=6.20 cm is positioned perpendicular to the magnetic field. When the switch is closed, a current of 3.65 A3.65\text{ A}3.65 A flows through the wire from point Q towards point P.
When the current is switched on, the reading on the electronic balance decreases by 0.780 g0.780\text{ g}0.780 g from its initial zeroed value.
State the direction of the magnetic force acting on the wire PQPQPQ.
Using Fleming's Left-Hand Rule, if the reading on the balance decreased, state the magnetic poles of the faces adjacent to the wire (left magnet and right magnet).
Define the tesla.
Calculate the magnetic flux density BBB between the magnets. Assume the field is uniform within the magnet length and zero elsewhere.