Thursday, October 25, 2012
Lab Report 6Introduction and Faraday’s Law
Objective: In this experiment, Faraday’s law of induction will be investigated.
Theory: Faraday’s law of induction states the induced emf or voltage in a coil is proportional to the rate of change of magnetic flux through a coil, this is shown blew:
Ƹ= -dɸ/dtEquation 6.1
The flux of the magnetic field is defined and the following:
ɸ=BAcosΘ Equation 6.2
B is the magnetic field at the location of the coil. A is the cross sectional area of the coil, and Θ is the angle between the field and the area A. There is several different ways to create a changing flux though the coil. An easy way is to use a magnet moving near the coil to change B passing through the coil. Another way is to change B is to use a magnetic field B using another coil. If the tne current in the primary coil is changed, then the magnetic field through the secondary or pick up coil changes inducing a voltage.
Procedure: Start by setting up Logger pro and attaching the required equipment. A) Use a compass to determine the north. Change the sample rate on logger pro to 20-30 samples in 5 seconds. Collect data while moving a magnet toward the coil. Repeat what just was done but move the magnet away from the coil. Compare the differences of the two runs. Then run a magnet to and from the side of the coil and observe what happens. B) Attach a sine wave generator to a 200 turn coil. Insert an AC ammeter rated to at least 2 Amps into the circuit to the monitor the current through the primary. Place the pickup coil at the center of the primary coil. Set sample rate to 1000 sample in 1 second. Collect several runs. Then turn the pick up coil sideways. Collect data and observe what happens.
Graph 6.1: this graph shows a sample of the data for procedure A.
Graph 6.3: this graph shows the information collected for procedure...