A good scientist must understand the scientific principles involved in his science project and ask questions to stimulate further discovery. Read books and websites to research the science behind electricity. Pose a question such as "Which chemical solutions best conduct electricity?" "How does static electricity work?" "What happens when you blow a fuse?" or "Which battery brand lasts the longest?"
A hypothesis is an educated guess based on the scientific knowledge you have collected. Consider the evidence of known electrical science and predict the results of the experiment in measurable terms. For example, "The salt solution will produce the greatest voltage," "The circuit wire will break when charged with an electrical load greater than its capacity" or "X Brand battery will keep a flashlight lit the longest."
The experiment must measure the variables one at a time for easy measurement and comparison. Set up a testing procedure to test each individual variable and measure it against your hypothesis. For instance, in the conductivity experiment, each solution should contain only one chemical to isolate the effects of only that one factor and eliminate any doubts as to what else might be affecting the results; measure the voltage output of each with a multimeter. In the battery experiment, you need identical flashlights for each setup so the only difference is the battery brand, and an observation schedule or video camera with a time and date stamp to pinpoint the moment at which each flashlight ceases glowing. Take pictures of each step of the experiment. Record the results of each test.
Compare the results with your hypothesis. Write a paragraph explaining whether you proved or disproved it and why you got the results that you did. Make graphs and charts of the data collected.
Scientists must be able to communicate their knowledge to their professional colleagues and the general public. Write a summary of the preparatory research, question, hypothesis and procedure to go with the results. Each section should be neatly typed or handwritten. Arrange the narrative descriptions, pictures, charts and graphs in chronological order on a tri-fold science fair display board. If possible, set up a demonstration of the experiment on the display table to allow viewers to witness science in action.