1. Physical Science Unit 8, Magnetism Electromagnetic Induction : a means of generating Alternating Current (AC) Unit 8 1

2. Electromagnetic Induction When a ______ is moved into a magnetic field, current is induced to flow in the wire If the wire is then pulled out of the field, current flows in the_____________. If the wire is stopped in the field, current ______flowing Current flows only when _____________or “cutting magnetic field lines”) 2

3. EM Induction (cont.) To get more current, use _____ _______ and move it faster in the field. To get even more current, use __ ________ __ _______ and spin it in the field. From this, you get current that flows first in one direction, and then the other. Since the current alternates in direction, it is called Alternating Current (AC). 3

4. EM Induction (cont.) To generate AC electricity, we need to spin a loop of wire that is suspended in a magnetic field __________ ___________operate this way Sometimes gasoline is used to spin the loop (portable generators running on construction sites, or as back-up power source in ________, in ____________, etc.) 4

5. Large Scale AC Generation To generate large amounts of AC electricity, we need to _________________ _________________________________ Power plants in this country generate large amounts of electricity using various types of mechanical forces Goal is to spin a coil of wire in a magnetic field, which generates AC electricity 5

6. Ways to Spin the Coil of Wire 1)By projecting _________through a turbine. This is the major way (right now) that electricity is generated in this country 2)Water falling through a water wheel (called a ____________) spins the coil. This is called _________________. 3)Wind blowing through a ______________. Wind can be “harvested” and made into electricity in _______ __________ 6

7. Steam is produced by: __________ _______. Large-scale coal plants produce vast amounts of electricity Burning ___________ ______. Sometimes in co-generation, or combined cycle plants. Nuclear reactions, in nuclear power plants Other alternative sources are ___________, __________, ___________, ____________, 7

8. Renewable vs. non-renewable Renewable Wind Solar Geothermal Water Non-Renewable Coal, fossil fuel Wood and Biomass (takes more than 10 years to replace) Natural Gas Nuclear http://www.bbc.co.uk/schools/gcsebitesize/geography/energy_resources/energy_rev1.shtml 8