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Electrical Current Autumn Mitchell, Aaron Cathcart, Heston Forson, Colby Borreson
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State And Explain Major Concepts Alternating current is the electric current that rapidly reverses in direction, usually at the rate of 60 hertz (in North America) or 50 hertz (in most other places). Ampere is the SI unit of electric current. Direct current is the electric current whose flow of charge is always in one direction only. Electrical resistance is the resistance of a materiel to the flow of and electric current through it; measured in Ohms. Electric current is the flow of electric charge; measured in amperes. Electric power is the rate at which electric energy is converted into another form, such as light, heat, or mechanical energy. Ohm is the SI unit of electrical energy. Ohm's law is the statement that the current in a circuit is directly proportional to the voltage impressed across the circuit inversely proportional to the resistance of the circuit. Potential difference is the difference in electric potential, or voltage, between two points. Voltage source is a device, such as a dry cell, battery, or generator, that provides a potential difference.
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Historical Perspective Italian physicist Alessandro Volta discovered that particular chemical reactions could produce electricity, and in 1800 he constructed the voltaic pile (an early electric battery) that produced a steady electric current, and so he was the first person to create a steady flow of electrical charge "Who Discovered Electricity? - Universe Today." Universe Today. 2014. Web. 22 Feb. 2016.
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Application of Concepts Electric currents are a huge part of our daily lives. These currents are used throughout peoples' homes in electric outlets. The outlets are used to power our electric appliances like TV's and lamps. The voltage that is produced in these home outlets is 120 volts and that is what is used to power the electric appliances.
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Think and Explain. Ampere and volt measures two different things. Amperes measures the electrical current while volts measures the electric potential difference. An ampere is a flow. 2. The current is 2 amperes. 3. It would supply 6 volts. 4. 8 volts are required. 5. If The voltage and resistance are doubled, the current will remain the same because both the voltage and resistance cancel each other out. The same effect will happened if both are halved. 6. 0.005 amperes will move through your fingers. 7. Wires heat up when they carry large currents because the electrons bump into metallic ions and lose some kinetic energy, which causes the heat. 8. Thick wires are used because they show less resistance, which makes it so that they don’t heat up easily and melt like thin wires would. 9. The electrical system in a car is powered by a battery so it is DC; electricity in a home is powered by an alternating current generator so it is AC. 10. 1/2 an ampere flows through a120 volt circuit connected to a 60 watt bulb. 11. 10 amps of current is drawn by a 1200 watt hair dryer operating on 120 volts. the resistance of the hair dryer is 12 ohms. 12.The two headlights together draw 6 A, which means that a 60 amp-hour battery will be dead in no more than 10 hours (60 amp-hours ÷ 6 amps).
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Review Questions 1) Heat flows through a conductor when a difference in temperature exists across its ends. 2) Difference in voltage across the conductor 3) The water will flow as long as a difference in water level exists. The flow will cease when the pressures at each end are equal. 4) The flow of electric charge 5) Electric current is measured in amperes. 6) Dry Cells & Wet Cells 7) 80 Joules 8) Charges flow through a circuit 9) Voltage goes across a circuit 10) The resistance that the conductor offers to the flow of charge 11) Electrical resistance is less in thick wires and the longer the wire the greater the resistance 12)The relationship between voltage, current, and resistance 13) current and voltage are proportional so you'll get twice the current for twice the voltage. 14) if the resistance is doubled for a circuit, the current will be half what it would be otherwise 15) your body has less ohms if you are soaked with water 16) distilled water is usually a good insulator but ordinary water greatly reduces electrical resistance 17) because the bird is touching nothing else with different current potential other than the wire 18) the third prong connects the body of the appliance directly to the ground 19) a battery produces direct current and a generator produces an alternating current 20) pattern of oscillating motion 21)in a typical dc circuit electrons have a net average drift speed of about 0.01 cm/s and in an ac circuit the conduction electrons don’t go anywhere 22) they vibrate to and fro in relatively fixed positions 23)the rate at which work is done 24) kilowatt-hour is electric energy but watt and kilowatt are units of power. 25) 0.5 amperes
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Background Report If the two requirements of an electric circuit are met, then charge will flow through the external circuit. It is said that there is a current - a flow of charge. Using the word current in this context is to simply use it to say that something is happening in the wires - charge is moving. Yet current is a physical quantity that can be measured and expressed numerically. As a physical quantity, current is the rate at which charge flows past a point on a circuit. As depicted in the diagram below, the current in a circuit can be determined if the quantity of charge Q passing through a cross section of a wire in a time t can be measured. The current is simply the ratio of the quantity of charge and time. http://www.physicsclassroom.com/class/circuits/Lesson- 2/Electric-Current
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Question or Hypothesis Question: Will all fruit and vegetables produce a recognizable amount of volts. Hypothesis: We hypothesize that all fruit and vegetables will produce volts.
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General Statement We will first take a banana, orange, and potato and connect them with a copper wire and galvanized material. Then someone will hold the tips of each metal close together to generate volts and see that when a phone is connected if it measures that there is power being generated.
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Materials Banana Orange Potato Copper wire Galvanized material Phone charger Phone
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Step-by-Step instructions 1) Collect all materials. 2) Set up the potato with the equipment 3) Connect the phone charger with the connecting wires. 4) Have the phone connected to the potato for 2 minutes. 5) Record if the phone has charged or not. 7) Repeat steps 2 through 5 with the banana and orange.
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Safety Precautions Don't electrocute yourself too bad from the fruit or potato.
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Table of Results Produce Being TestedDid it Produce Enough Volts To Charge the Phone Banana No Orange No Potato No None of the tested produce produced enough volts to have the phone recognize that it was being charged.
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Analysis When performing our experiment, we found that the potato, orange, and banana did not produce any charge on the phone.
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Conclusion Our hypothesis was incorrect because the potato, orange and banana were able to charge the phone
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Evaluation of Hypothesis In our question we asked if all fruits and vegetables would produce a recognizable amount of volts and with that, we hypothesized that they would. Sadly our hypothesis was wrong and we can answer our question with a no. Neither the orange, banana, or potato produced a register able amount of volts.
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