# PHYSICS LAB HELP - RC circuit

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1. Oct 12, 2014

### AGGENGR

• Warning! Posting template must be used for homework questions.
Consider a series RC circuit with an
R = 3.0 Ω
and a capacitance of 12 µF being charged to a voltage of 5.0 V. (Note, you will not include units in your answers.)

If you wished the charging of this capacitor to have a vertical displacement of 4.0 DIV from 0 charge to fully charged, what value must you set the vertical gain on the oscilloscope to achieve this?
- FOUND THIS ONE: 1.25 V/DIV

What is the value of the horizontal sweep that you would need to use if you wished the characteristic time constant of this circuit to span 2.0 DIV on the oscilloscope screen?

-LOST HERE.

So i am having trouble understanding the last part and am down to one try...we are also doing this lab BEFORE having covered this in lecture soo im kinda lost....

2. Oct 12, 2014

### Staff: Mentor

Look up characteristic time for an RC circuit. It is a simple formula, use it and the second part is very similar to the first part.

3. Oct 12, 2014

### AGGENGR

I tried looking this up but am not sure what you mean?

Again we just started RC Circuits so im a little lost..

4. Oct 13, 2014

### andrevdh

The characteristic time is related to the time constant of the RC circuit.

5. Oct 16, 2014

thanks!