Show that Q is proportional to V for capacitor

[jsmith613]

Homework Statement

Describe how you would show experimentally that the charge stored on a 220 µF capacitor is proportional to the potential difference across the capacitor for a range of potential differences between 0 and 15 V. Your answer should include a circuit diagram.

Homework Equations

The Attempt at a Solution

- charge the capacitor for a given Voltage, V
- ensure the capacitor is charging at a constant rate by varying the resistance of the variable resistor --> ensures current remains constant
- Q=It (current * time take for capacitor to charge)
- capacitor is charged when V on meter = V of supply
- Q/V = constant for range of values of V

Is this method correct - would it work?

p.s: I am aware my diagram is not very well drawn - i will obviously improve this in the exam

 

[truesearch]

V is easy to measure...do you know of any way to measure Q?

 

[jsmith613]

V is easy to measure...do you know of any way to measure Q?

my syllabus only talks about coloumbmeters but the MS said the a coloumbeter would be insufficient for this experiment because the capacitance is too high.

I was simply wondering, would my method work?

 

[MalachiK]

Your method sounds good to me - although it might be a bit tricky keeping the current constant unless the capacitor was charging very slowly.