The Emf Induced Across A Moving Straight Conductor

The Straight Conductor The straight conductor can be thought of as a a single turn coil stretched out

The emf generated by a single turn coil is: Where n=1 Remembering A stationary straight conductor does not enclose any area but as it moves it sweeps out an area each second

A=l x x Length l Distance moved perpendicular to the field (x)

In a uniform field B does not change and the length of the conductor stays the same so we can write Where B is the flux density l is the length of the conductor perpindicular to the field v is its velocity

Example 1 An aeroplane with wingspan 20.5m travels south to north at 310ms-1 a region where the vertical component of the Earth magnetic field is 3.0 x 10-5T. What is the emf generated between the wingtips?

Example 2 A patient is pushed into an 3.2T MRI scanner at 1ms-1. The patient has a 5cm tungsten pin through the bone of one leg at 900 to the field lines during this process. What is the emf generated between the ends of the pin? What would happen if the pin was made of steel?

Example 3 A 2m scaffolding pole falls from a tall building. It falls horizontally pointing East to West for 2 seconds. What is the average velocity of the falling pole? What is the average emf generated between the ends of the pole as it falls. (Horizontal component of the Earth field 5.4 x 10-5T, Vertical Component of the Earth field 3.4 x 10-4 T)