A straight, horizontal copper wire of length 75 mm is positioned perpendicular to a uniform horizontal magnetic field inside a calibration balance. When the electric current in the wire is decreased by 2.4 A, the magnetic force acting on the wire decreases by 1.17 × 10-2 N.
What is the magnetic flux density of the field?
6.5×10−5 T6.5 \times 10^{-5}\text{ T}6.5×10−5 T
3.7×10−4 T3.7 \times 10^{-4}\text{ T}3.7×10−4 T
6.5×10−2 T6.5 \times 10^{-2}\text{ T}6.5×10−2 T
1.5×101 T1.5 \times 10^1\text{ T}1.5×101 T
66 exam-style questions on AQA A Level Physics Magnetic fields (A-level only), covering Magnetic flux density (A-level only), Moving charges in a magnetic field (A-level only), Magnetic flux and flux linkage (A-level only), Electromagnetic induction (A-level only), Alternating currents (A-level only), and The operation of a transformer (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.