EECE 5320  Generator PhET Lab  
Introduction:
Why was Hoover Dam (Boulder Dam) built eighty years ago? In 1936 the
generators in the dam started transmitting power to Los Angeles and later
generators were brought online to power other cities, including your
hometown. When high-pressure water flows through the dam’s power plant,
the water turns turbines in generators. A magnet in the generator spins in the
generator’s magnetic field. This moving-magnet-in-a-magnetic field causes
electrons to move, eventually ending up in your TV, ipod, Wii, etc. 
 Procedure, Part I: PhET Simulations  Play With Sims  Electricity, Magnets, and Circuits  Generator 
 Part II: A Moving Magnet in a Magnetic Field (Pickup Coil) 
 Part III: Creating a Magnetic Field (Electromagnet) 
 Part IV: More Than Meets the Eye (Transformer) 
 Part V: The Colorado River Runs Through It (Generator) 
 Conclusion Calculations and Questions:
1. If the number of loops in a coil around a moving magnet doubles, the emf created doubles / halves / remains the same.
2. If area of a coil around a moving magnet doubles, the emf created doubles / halves / remains the same
3. If the speed of a moving magnet through a coil doubles, the emf created doubles / halves / remains the same
4. When the polarity of a moving magnet in a coil is flipped, the emf increases / decreases / remains the same.
5. As current increases in an electromagnet’s coil, the strength of the created magnetic field increases / decreases /
remains the same.
6. A DC electromagnet creates a changing / constant magnetic field and an electromagnet powered with AC creates a
changing / constant magnetic field.
7. In a step up transformer, the emf (voltage) is stepped up and the _current is stepped down.
8. The power output of a step up transformer is greater than / less than / the same as the input power of the transformer.
9. 9.0 volts are sent into a transformer with a 10-coil primary loops and a 30-coil secondary loop. The voltage leaving the
secondary loop will be 27 V
10. The power output of a transformer is 100. W. The input voltage is 25V. What is the coil-turn ratio of the transformer
if the output current is 1.0 A? 1:4