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HAND CRANK GENERATORS [15 minutes](Teacher Version) Intro: Energy is neither created nor destroyed, but converted from one form to another. The majority of our electricity (how we power our homes, schools, etc.) comes from generators that convert mechanical energy into electrical energy and thermal energy *In this experiment, students learn that it takes spinning a generator (mechanical energy) to create the electricity (electrical energy) to power a light bulb. * Background: There are a limited number of methods to generate electricity: 1) Static electricity, 2) Electromagnetic induction (turning a generator), 3) Photoelectric effect (solar panels), 4) Nuclear transformation (decay releases charged particles), 5) Thermo-electric effect, and 6) the Piezoelectric effect. The majority of our electricity comes from generators (electromagnetic induction). A generator converts mechanical force into electrical current. Inside a generator we have coiled wire (usually copper) and magnets. When we spin the wire near a magnet, we can induce the flow of electrons in the wire. This flow of electrons is electricity. Materials: Antique telephone hand-crank generator Plastic generators Light bulb stand, 10 W incandescent, fluorescent, LED light bulbs, Alligator clips Procedure: 1) With old-fashioned hand-crank generator: a) Connect black and red alligator clips to the terminals on the generator and connect the other ends of the clips to the light bulb stand. b) Screw in 1 of the 3 light bulbs (low wattage incandescent, LED, or fluorescent). c) Turn the handle to power the light bulb. d) Repeat with the other two bulbs 2) With modern plastic generators: a) Use alligator clips to connect two generators in a row, positive to positive and negative to negative b) Turn the crank of one generator and watch what happens to the second generator’s crank (note the speed at which both are turning and direction). *Mention that their light bulbs (and other devices powered by electricity) are all connected to power plants, which have big generators being turned by steam. The steam is made by heating water through the burning of fuels like coal, natural gas, or nuclear reactions. * HAND CRANK GENERATORS [15 minutes] Intro: Energy is neither created nor destroyed, but converted from one form to another. The majority of our electricity (how we power our homes, schools, etc.) comes from generators that convert mechanical energy into electrical energy and light. Background: There are a limited number of methods to generate electricity: 1) Static electricity, 2) Electromagnetic induction (turning a generator), 3) Photoelectric effect (solar panels), 4) Nuclear transformation (decay releases charged particles), 5) Thermo-electric effect, and 6) the Piezoelectric effect. The majority of our electricity comes from generators (electromagnetic induction). A generator converts mechanical force into electrical current. Inside a generator we have coiled wire (usually copper) and magnets. When we spin the wire near a magnet, we can induce the flow of electrons in the wire. This flow of electrons is electricity. Materials: Antique telephone hand-crank generator Plastic generators Light bulb stand, 10 W incandescent, fluorescent, LED light bulbs, Alligator clips Infrared camera Procedure: 1) With old-fashioned hand-crank generator: c) Connect black and red alligator clips to the terminals on the generator and connect the other ends of the clips to the light bulb stand. d) Screw in 1 of the 3 light bulbs (low wattage incandescent, LED, or fluorescent). e) Turn the handle to power the light bulb. f) Repeat with the other two bulbs 3) With modern plastic generators: a) Use alligator clips to connect two generators in a row, positive to positive and negative to negative b) Turn the crank of one generator and watch what happens to the second generator’s crank (note the speed at which both are turning and direction). 4) Create a series circuit with a fluorescent and an LED bulb. a) [insert image here] b) Crank the generater and observe the fluorescent bulb with the camera. What is happening? Questions 1) What happens when you stop turning a generator? 2) What is the role of switches in your home? 3) Are you making energy from scratch? (What is converted to electricity, Rember conservation of energy) 4) What happens to the speed of the second generator? (efficiency) 5) What is the reverse of a generator? (give example)