- #1
displayname
- 6
- 0
Homework Statement
You are given a container with either a battery and a resistor or a capacitor inside it. There is also a positive and negative terminal sticking out of the container.
Without looking inside, how will you determine what is inside the container? Materials include a voltmeter, a voltage vs. time probe, wires and alligator clips, resistors, and batteries.
If it is a batter and resistor, how will you determine the voltage of the battery and the resistance of the resistor? If it is a capacitor how will you determine the capacitance (hint: graph voltage vs. time)?
Homework Equations
V=IR
V = Vo(e^(-t/RC))
The Attempt at a Solution
Find if battery of capacitor:
- attach a voltmeter in parallel to figure out initial voltage
- If there is 0 voltage, you have a capacitor.
- If voltage is not 0, attach a resistor for a second
- Remove resistor then measure the voltage again. If the voltage dropped significantly to 0 or close to 0, you have discharged a capacitor. Otherwise, if the voltage stayed about the same, you have a battery.
In order to confirm you have a capacitor, attach a battery to the circuit. Disconnect battery. See if voltage is not 0.
If you have a battery:
- find voltage by adding voltmeter in parallel
- find resistance by?
If you have a capacitor:
- add a resistor in series (note resistance)
- use the voltage over time probe and graph voltage over time
- get two voltage points and plug into the voltage of capacitor equation to solve for capacitance
Is this method right? How do i find resistance of a resistor? maybe use V = IR, but we don't know I