What is the charge on the capacitor when I = 2 mA?

  • Thread starter Thread starter christianerik
  • Start date Start date
  • Tags Tags
    Capacitors
christianerik
Messages
9
Reaction score
0
At t=0 the switch S is closed with the capacitor is uncharged.

..... 3M ohm... 102 micro F
--------------^^^^^--------ll-------------
l l
l ... s...<----i--->......l
l-------l i-------/.--------------------------l
17 V

What is the charge on the capacitor when
I = 2 mA? Answer in units of C.

Need some help understanding it...
 
Physics news on Phys.org
hello christianerik, welcome to PF

you know that C=Q/V

find the voltage between the resistance using the given values of current and resistance [since it’s connected in series with the capacitor, you should subtract this value from 17 volts to get the voltage between the capacitor plates]. then use the previous equation to solve.
 
christianerik, welcome to PF Forums! You will find many useful discussions and people willing to help you. Before we can do so, you need to show your own effort towards solving your problem. You may want to reread this https://www.physicsforums.com/showthread.php?t=94380" that is shown at the top of this topic. If you don't have a clue, start by stating all that you understand about your problem and lead us to the point where you are stuck.

Using the homework template that is given, when you initiate a thread, is also helpful no only to us but it also helps you organize the question more clearly. Some good examples of homework threads may be viewed https://www.physicsforums.com/showthread.php?t=131568".
 
Last edited by a moderator:
Your drawing's not clear. I suggest sketching on paper, or using drawing software and uploading the image. Also recommend double-checking the values in your question, particularly for the resistor & current.
 
Last edited:

Thread 'Please tell me where I am going wrong in this integral'

##|\Psi|^2=\frac{1}{\sqrt{\pi b^2}}\exp(\frac{-(x-x_0)^2}{b^2}).## ##\braket{x}=\frac{1}{\sqrt{\pi b^2}}\int_{-\infty}^{\infty}dx\,x\exp(-\frac{(x-x_0)^2}{b^2}).## ##y=x-x_0 \quad x=y+x_0 \quad dy=dx.## The boundaries remain infinite, I believe. ##\frac{1}{\sqrt{\pi b^2}}\int_{-\infty}^{\infty}dy(y+x_0)\exp(\frac{-y^2}{b^2}).## ##\frac{2}{\sqrt{\pi b^2}}\int_0^{\infty}dy\,y\exp(\frac{-y^2}{b^2})+\frac{2x_0}{\sqrt{\pi b^2}}\int_0^{\infty}dy\,\exp(-\frac{y^2}{b^2}).## I then resolved the two...
View full post »

Thread 'Direction of the magnetic field of an oscillating charge'

Hello everyone, I’m considering a point charge q that oscillates harmonically about the origin along the z-axis, e.g. $$z_{q}(t)= A\sin(wt)$$ In a strongly simplified / quasi-instantaneous approximation I ignore retardation and take the electric field at the position ##r=(x,y,z)## simply to be the “Coulomb field at the charge’s instantaneous position”: $$E(r,t)=\frac{q}{4\pi\varepsilon_{0}}\frac{r-r_{q}(t)}{||r-r_{q}(t)||^{3}}$$ with $$r_{q}(t)=(0,0,z_{q}(t))$$ (I’m aware this isn’t...
View full post »

Thread 'Initial conditions for orbits around a wormhole'

Hi, I had an exam and I completely messed up a problem. Especially one part which was necessary for the rest of the problem. Basically, I have a wormhole metric: $$(ds)^2 = -(dt)^2 + (dr)^2 + (r^2 + b^2)( (d\theta)^2 + sin^2 \theta (d\phi)^2 )$$ Where ##b=1## with an orbit only in the equatorial plane. We also know from the question that the orbit must satisfy this relationship: $$\varepsilon = \frac{1}{2} (\frac{dr}{d\tau})^2 + V_{eff}(r)$$ Ultimately, I was tasked to find the initial...
View full post »

Similar threads

Constraint force using Lagrangian Multipliers
Replies
6
Views
3K
How to find voltage across capacitor in RLC circuit?
Replies
3
Views
1K
Why Capacitors in Parallels vs. Series: Coaxial Capacitor Case
Replies
2
Views
2K
The potential of a sphere with opposite hemisphere charge densities
Replies
6
Views
3K
Oscillation of a driven RLC network
Replies
19
Views
3K
Why is solid density used in this thermodynamics problem?
Replies
5
Views
2K
LC oscillations - two capacitors and an inductor
Replies
15
Views
595
Capacitor charging: Where do extra electrons come from?
Replies
3
Views
817
Can anyone help check where I went wrong (Potential of electrodynamics)?
Replies
16
Views
2K
Ranking charge stored on three capacitors by a battery
Replies
6
Views
3K

Hot Threads

Recent Insights

Back
Top