Question

Moving charges will produce a local magnetic field, but the reverse is also true a changing magnetic field will similarly induce charges to move (ie. produce current). Consider a magnet moving into a coil of wire: A spinal coil of wire with many closely-spaced tums this is called a solenoid is connected to a micro-ammeter as shown in the diagram above. As the magnet moves into the coil, any induced current will be measured by the micro-ammeter. Question On the diagram above indicate the direction of current fiow in the microammeter. Magnetic Flux nus. Flux is a A common way to think about changing magnetic fields is to think about magnetic measure of the number offield lines passing through a region of space: more field lines means that the field is denser, closer to a pole and therefore more powerful. Field lines are technically not real, so flux is not exactly "real' either, but the concepts are useful because they are good metaphors for something that is definitely real-the strength of the magnetic field itself. Because of this, we define magnetic flux as the product of the magnetic field and the area through can we are defining the flux: Here is the magnetic flux, Bis the magnetic field, and A is the vector describing the area of the flux. The flux through an area A is the dot product of the area itself and the magnetic field passing through the area. When a magnet's North pole is pushed into a region of space like the solenoid, you should be able to imagine that the field lines in that region will increase (and therefore, so will the magnetic flux). The rate change in flux is proportional to the induced voltage and current. of Explaining Magnetic induction Lenz's Law The changing magnetic field (due to the moving magneto creates an induced voltage, which produces a current in the solenoid because voltage makes current flow) is current produces its own magnetic field. The induced current flows in a direction such that its own magnetic field opposes the change in magnetic field that was due to the moving magnet.

Answer 1