An analog measuring instrument utilizes a moving-coil system. It consists of a rectangular coil suspended in a uniform magnetic field between two permanent magnetic poles, as shown in the diagram below.
Explain why the coil rotates when a current passes through it.
A student is designing a portable backup generator and is choosing between a bicycle-style dynamo and a modern alternator. Describe two similarities and two differences in how these two generator devices function.
Suggest one way to increase the peak electrical output of these generator devices.
A straight horizontal copper rod in an electromagnetic launcher is aligned perpendicular to a uniform horizontal magnetic field of magnetic flux density 1.25 T1.25\text{ T}1.25 T. When a current of 4.8 A4.8\text{ A}4.8 A flows through the rod, it experiences an upward electromagnetic force of 0.54 N0.54\text{ N}0.54 N.
Calculate the length of the rod that is within the magnetic field.