Download Ms. Todd`s Honors Physics

Ms. Todd’s Honors Physics LAB: Series & Parallel Circuits THE SERIES CIRCUIT Name______________________________ Pd_________ Date________________ Lab Partners _____________________ _______________________ _______________________ Draw a sketch of how you would wire 3 light bulbs in SERIES, with the power source (in a second color). Include in your sketch an ammeter (in a third color) which will measure the current for one bulb and a voltmeter (in a fourth color) which will measure the voltage across one bulb. Now, in the space below, sketch a “schematic diagram” for the set up above, maintaining your color coding. (Try to make your schematic diagram as large as possible to leave room for measurements) THE PARALLEL CIRCUIT Draw a sketch of how you would wire 3 light bulbs in PARALLEL, with the power source. Include in your sketch an ammeter which will measure the current for one bulb and a voltmeter which will measure the voltage across one bulb. Maintain your color coding from your series circuit. Now, in the space below, sketch a “schematic diagram” for the set up above, maintaining your color coding. (Try to make your schematic diagram as large as possible to leave room for measurements) 2 Lab Part 1 – The Series Circuit: 1. Before plugging in your power source, turn down the output voltage on the power source to its minimum. 2. Wire the series circuit as you have sketched on page 1. Leave the ammeter and voltmeter out for now. 3. Connect the voltmeter to the power source. 4. Get your teacher to check your circuit. 5. Turn on the power source, and adjust the output to 6V. Do not change this voltage for the rest of the lab. 6. All three bulbs should go on. If it does not, call your teacher over. 7. Remove one of the bulbs from its housing. (If this is impossible, disconnect one end of one of the bulbs.) What happens to the other two bulbs? 8. Reconnect the bulb. 9. Wire an ammeter to measure the current going through one of the bulbs. Label your measurement on your schematic diagram on page 1. 10. Measure the current in the other two light bulbs and record on your schematic diagram. 11. Label the total current going through the circuit next to the power source. 12. Use the voltmeter to determine the voltage drop across each bulb and across the power source. Label the voltages you find next to each circuit element in your schematic. 13. Turn off your power supply. 14. Calculate the resistance of each bulb and record in your schematic. 15. Calculate the power of each bulb and label on your schematic. Then calculate the total power of the circuit and place that number next to the power supply in your schematic. Lab Part 2 – The Series Circuit: 1. Before plugging in your power source again, wire the parallel circuit as you have sketched on page 2. Leave the ammeter and voltmeter out for now. Your power source should still be at 6V. 2. Get your teacher to check your circuit. 3. All three bulbs should go on. If it does not, call your teacher over. 4. Remove one of the bulbs from its housing. (If this is impossible, disconnect one end of one of the bulbs.) What happens to the other two bulbs? 5. Reconnect the bulb. 6. Use the ammeter to measure the current going through each bulb and record on your schematic diagram on page 2. Also label the total current going through the circuit next to the power source. 7. Use the voltmeter to determine the voltage drop across each bulb and across the power source. Label the voltages you find next to each circuit element in your schematic. 8. Calculate the resistance of each bulb and record in your schematic. 9. Calculate the power of each bulb and label on your schematic. Then calculate the total power of the circuit and place that number next to the power supply in your schematic. 3 CONCLUSION: Compare the SERIES CIRCUIT with the PARALLEL CIRCUIT, looking at both individual bulbs and the total circuit. Record your observations below: a) Voltage: b) Current: c) Resistance: d) Power: e) Brightness: 4