You will get a shock any time that two parts of your body are at differentpotentials. The larger the potential difference, the larger the shock.Do not touch any of the exposed metal on the conducting wires whenthe power supply is on. It is safe to touch the rubberized outer coating ofthe wires, however. The rubber insulation is there to keep the wires fromconneting with other wires other than at their end junctions. It also keeps youfrom receiving shocks.
Ammeters MUST be connected in series. If the ammeter is connected inparallel with the resistor, a large current will pass through the meter'sinternal resistance - burning out the circuit. Make sure that your ammeter isconnected in series and that it is set to its highest setting, 20A.
The lightbulbs in this experiment are rated to 3V (screw base) or 6V (plugbase). If an individual bulb is connected to a potential difference greater than its rating, the bulb will no longer be useful. You need three bulbs to complete this experiment. You will be given four. Ifyou blow more than one bulb because you were careless, you will have to accepta grade of zero points for those portions of the experiment that you wereunable to complete because you didn't have enough bulbs. If you make sure that the power supply is off when connecting the bulbsor meters AND if you turn the power up from zero very slowly, you shouldn'thave problems blowing the bulbs.
Make sure all connections are tight. Jiggling of loose connections willaffect the electrical connection and can affect the current by 10%.
Complete and concise records of your observations are very important. Answer any questions in the lab manual while you are in lab, then use thoseobservations when writing your report. Part of your grade will be the clarityand completeness of your observations.
Analyzing your observations means summarizing what you saw and discussingany conclusions you draw from those observations. Make sure to support your conclusions by refering to your data. For example, if you conclude that the voltage a parallel circuit is the same for each bulb in parallel, you should support that conclusion using your data. Remember to use proper paragraph formfor your discussions.
Ammeters: Can current flow through the circuit withough the bulbbeing lit? How Does the appearance of the filament change as the currentincreases?
Voltmeters:How does the voltage across the bulb compare to thecurrent through the bulb?
Series Circuits: What conclusions can you draw as to the current andvoltage behavior in series circuits? Be thorough and be specific in yourdiscussion.
Parallel Circuits: What conclusionss can you drraw as to the currentand voltage behavior in parallel circuits? Be thorough and be specific in yourdiscussion.
Based on your observations in the laboratory, would you say that the lightsin your home are connected in series or in parallel? Explain the reasoningbehind your answer.
| Section | Points |
|---|---|
| Purpose | 1 |
| Results | 3 |
| Observations | 6 |
| Conclusions | 10 |