Lab Simulation: Changing Magnetic Fields

In this lab you will investigate how a changing magnetic field can induce an electrical current in a conductor.  For the generator effect to occur, there must be relative motion between an external magnetic field, such as that produced by a bar magnet, and a conducting wire.  By forming the conducting wire into a loop, the generator effect can be amplified and observed using a galvanometer (to measure the current) or a voltage meter (to measure the charge separation as a result of the current).

 

Problem

 

What factors increase the current produced in a generator?

 

Materials

 

" Faraday's Electromagnetic Lab " simulation (note, you may need to open this file in FireFox)

 

Procedure

  1. Open "Faraday's Electromagnetic Lab" simulation.  Select the "Pickup Coil" tab at the top of the simulation window and select the voltage meter instead of the light bulb as the indicator.
© PhET Interactive Simulations, University of Colorado. Some rights reserved.

 

  1. Move the bar magnet back and forth through the loop of wire, and observe the voltage meter.  

  2. Switch the indicator back to the light bulb, and move the magnet through the coil.  Try moving the magnet at different speeds.  Then try moving the coil.  

  3. Select the "Generator" tab at the top of the simulation window and turn the water tap on by sliding the lever as indicated below.  Observe the magnitude and direction of the voltage as the magnet spins.
© PhET Interactive Simulations, University of Colorado. Some rights reserved.

 

  1. Adjust the magnetic strength and observe the magnitude of the voltage meter swing.

  2. Adjust the water flow and observe the magnitude of the voltage meter swing.

  3. Adjust the number of loops and observe the magnitude of the voltage meter swing.

  4. Adjust the loop area and observe the magnitude of the voltage meter swing.

 

Self-Check

Answer the following self-check (SC) question then click the "Check your work" bar to assess your response.

 

SC 3.  

Based on your results from the lab you just completed, which of the three coils in "Figure 12.37" in the "Inquiry Lab" would produce the most current?

 

    Self-Check Answer

Contact your teacher if your answer varies significantly from the answer provided here.

 

SC 3.  

The larger loop would produce the most current.