Are These Capacitors in Series or Parallel?

AI Thread Summary
The discussion revolves around the configuration of capacitors in a lab experiment, questioning whether they are in series or parallel. The lab write-up indicates that two capacitors, a 0.1uF and a 1.0uF, are connected to form a 1.1uF capacitor, which should be in parallel. However, confusion arises when a charged 1.0uF capacitor is connected to the 1.1uF capacitor, leading to a voltage reading of 2.485V instead of the expected voltage distribution. Participants suggest verifying the calculations for both series and parallel configurations to clarify the observed voltage. The discussion highlights the importance of understanding capacitor connections to ensure accurate experimental results.
PhysicsMark
Messages
90
Reaction score
0

Homework Statement



I have some results of my lab here and I just want to check to make sure they make sense. The lab write-up refers to this part of the experiment as "capacitors in parallel" but I think they are actually in series (either that or we connected them incorrectly).

Here is a portion of the lab write-up:

For the formal experiment, begin with a pair of capacitors in parallel. Place a .1uF (the "u" should read as micro) mounted across the input of the voltage follower and mount a 1.0uF capacitor on a styrofoam block; connect the 2 capacitors to create a 1.1uF capacitor. Make sure that the 1.1uF is completely discharged. Charge a second 1.0uF capacitor to 5.0V and touch it to the uncharged 1.1uF capacitor. For safety, discharge the "charge-transfer" capacitor before putting it down. Compare the measured voltage to what is expected from a theoretical calculation.

Our DVM (which was attached to the voltage follower) read 2.485V.

I am confused because this part is labeled capacitors in parallel but it seems to me that when we touched the charged capacitor to the 1.1uF capacitor we made a series circuit, and that is why the voltage was not constant.

Does this seem right to anyone?


Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
It says to connect the 1 and the .1 to make a 1.1 microfarad capacitance, so you should have connected them in parallel. That is, connect them together at one end and also at the other end.

However, in this case when you touch the 1 μf capacitor (1 nearly equal to 1.1) you ought to get about half of the 5 Volts on each rather than 2.485 V.
Perhaps you can work out what the capacitance and voltage are if they are in series and see if that works out to about the 2.4 V.
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top