An experiment is set up to determine the magnetic flux density BBB between the poles of a permanent magnet.
The magnet is placed on the digital balance. The current-carrying wire is horizontal, fixed in place, and oriented at right angles to the magnetic field between the poles of the magnet.
The following data are collected:
- Length of the wire in the uniform magnetic field of the magnet = 8.0±0.2 cm8.0 \pm 0.2 \text{ cm}8.0±0.2 cm
- Balance reading with no current in the wire = 90.0 g90.0 \text{ g}90.0 g
- Balance reading with current in the wire = 91.5 g91.5 \text{ g}91.5 g
- Current in the wire = 2.5±0.1 A2.5 \pm 0.1 \text{ A}2.5±0.1 A
Calculate the magnetic flux density BBB, including its absolute uncertainty. Ignore the absolute uncertainty in the balance readings and use g=9.81 m s−2g = 9.81 \text{ m s}^{-2}g=9.81 m s−2.
Give your value for BBB to 2 significant figures and its absolute uncertainty to 1 significant figure.