試題詳解

14. Suppose we use a Hall probe to measure the magnitude of a constant magnetic field. The Hall probe is a strip of copper with a height of 1 mm. We measure a voltage of 0.15 µV across the probe when we run a current 2 A through it. What is the magnitude of the magnetic field? (The density of copper is 8.96 g/cm3, and 1 mole of copper is 63.5 g and each copper atom has one conduction electron)
(A) 0.5 T,
(B) 0.8T,
(C) 1.02 T,
(D) 2.1 T.