An experimental setup is designed to measure the magnetic flux density of a magnetic assembly using a sensitive digital balance. A heavy U-shaped steel yoke holding two rectangular magnets is placed on the balance pan. The magnets produce a uniform horizontal magnetic field in the gap between them. A rigid, horizontal copper rod of length L=6.20 cmL = 6.20\text{ cm}L=6.20 cm is fixed to an external stand so that it remains stationary, passing perpendicularly through the magnetic field between the two magnets.
The plan view of this setup is shown below:
Initially, the digital balance is zeroed. When a switch is closed, a current of 3.40 A3.40\text{ A}3.40 A flows through the copper rod from point P to point Q. This causes the reading on the electronic balance to decrease by 0.780 g0.780\text{ g}0.780 g.
State the direction of the magnetic force acting on the copper rod PQPQPQ.
Using Fleming's Left-Hand Rule, determine which of the magnet faces adjacent to the rod (Left magnet or Right magnet) is the North (N) pole and which is the South (S) pole. Explain your reasoning.
Define the tesla.
Calculate the magnetic flux density BBB between the magnets, assuming the magnetic field is uniform within the magnet length and zero elsewhere.