* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Electricity Lab (Teachers Edition)
Fault tolerance wikipedia , lookup
History of electromagnetic theory wikipedia , lookup
Electric battery wikipedia , lookup
Stray voltage wikipedia , lookup
History of electric power transmission wikipedia , lookup
Buck converter wikipedia , lookup
Current source wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Electrical substation wikipedia , lookup
Flexible electronics wikipedia , lookup
Mains electricity wikipedia , lookup
Rechargeable battery wikipedia , lookup
Regenerative circuit wikipedia , lookup
Alternating current wikipedia , lookup
Rectiverter wikipedia , lookup
Integrated circuit wikipedia , lookup
Earthing system wikipedia , lookup
Electrical wiring in the United Kingdom wikipedia , lookup
Circuit breaker wikipedia , lookup
Name: ________________________________ Per: _______ Date: ___________________ Electricity Lab1 (Teachers Edition) Question for this Investigation: How does electricity work inside our electronics? Materials2: 6-10 wires with “alligator” clips on ends 2 battery holders 3 light bulbs in holders 2 knife switches 2 “D” batteries Digital Multimeter Procedure: 1. Build the circuit shown in the diagram with one battery, a switch, and a bulb. Questions! 1. How can you tell the electric current is flowing in the circuit? Can you see the current flow? The lightbulb turns on. No. 2. How does the switch cause current to stop flowing? How can you tell? It breaks the circuit. The lightbulb turns off. 3. What do you think will happen if you flip the battery around? (It can be whatever they say.) 4. Try it! Was your prediction correct? What changed in the circuit once you switched the battery around? Something about how the current can still flow, maybe backwards. Electric En (wires) 5. Draw a diagram of the direction energy flows through the circuit. Label the forms of energy that appear. Chemical Energy 1 Modified from Hsu, Tom. Investigations: Physics, A First Course. CPO Science. Peabody, MA. 2005. pp.57-68. These are the basic components of Hsu’s Electric Circuits kit without the potentiometer, other components, and some extra lightbulbs. If you have the funds, buying the kit from CPO is a great (and easier) idea than assembling all this yourself. 2 Rad Hea 2. Circuit diagrams are used to simplify drawing electric circuits. In a circuit diagram, wires are solid lines and other electric devices have their own symbols. In the space below, draw a circuit diagram of the circuit you just made in step 1. You will not use all the symbols in the table. Battery Resistor Cell Wires Light bulb Switch 3. Make your circuit! Go ahead and try building a new circuit of your own design. Once you make one that works, draw its circuit diagram below. Use the correct symbols! Questions! 1. When you created your own circuit did it work the first time you tried connecting everything? What do you think was the most important thing that caused it to work? No. I actually connected all the parts to circuit and then It worked. 4. What is the use of a battery? A battery acts as a power source to push electrons around a circuit and thus, creates electricity. The battery’s strength is called voltage and measured in Volts (V). Find the voltage written on your battery and write it down here: _1.5 V____ To check the real voltage of your battery, use the digital multimeter to test it. Set the dial to DC Volts (V—) 2V. The red lead goes to the positive terminal and black to the negative. Touch two points in a circuit with the leads and the meter reads the voltage between the two points. Questions! 1. Make a prediction for what will happen if you add another battery to your circuit. Any answer will do but specifically, it will increase the light output in the bulb. 2. Now take a second battery and place it in the circuit “end to end” with the first battery. Make sure that they are connected + to -, otherwise your circuit will not work. Was your prediction correct? Describe any changes in the circuit that you observe. Yes, the light bulb got brighter. 5. Measuring voltages. Using a working circuit and the digital multimeter, try measuring the voltages “across” different objects (wires, light bulbs, switches). When we say “across” we mean placing a multimeter lead on the metal on one of side of an object and the other lead on the other side. Write down the measurements you get in the table below. Object Voltage (V) Lightbulb 1.38 V Wire 0 Switch 0 Question! 1. Do you notice anything significant about the voltages of the objects in the circuit? They all add up to the voltage of the battery! 6. What is electric current? If your circuit is not is not in the original configuration, please remake it to that now (procedure step 1). Leave the switch open so no electricity is flowing. Also, turn the dial of the multimeter to DC A (A—) at about 100 mA, which means direct current measured in milliAmperes. Remember, electric current is the amount electrons flowing in a circuit over time. To measure it, the multimeter must be connected so the current has to flow though it only. No other path may allow the current to bypass the multimeter. You know you are doing this correctly if the light bulb lights up only when you measure with the multimeter. Questions! 1. How much current is flowing in the circuit when the bulb is making light? Between 50 - 200 mA 2. In physics, we say current flows from the positive terminal of a battery or power source to the negative end. Return to your first circuit diagram you drew and draw arrows around the circuit showing the direction of current flow. See above. Conclusions 1. Though our favorite electronics are much more complicated than the circuits we just made, there are some similarities. Describe at least two of those similarities. These circuits are similar to my electronics in that they both use batteries and they both have wires. They also both have pieces that use electricity for something. Extra Credit (5 points) 1. Create your own circuit (or remake the one you made in step 3) and draw its circuit diagram below (if you’re doing the one from step 3 you do not have to redraw it). Measure the voltages across different objects and the current flowing through the circuit. Make tables like the ones in the lab to show your data. We just used our circuit drawing in part 3. Object Voltage (V) Current: 86 mA Lightbulb 1.38 Lightbulb 1.35 2 batteries 2.7