Calculating Capacitance: Series vs Parallel

In summary, the conversation discusses solving a question in a physics book involving two capacitors. The method used involves assigning charges and assuming potentials. The questioner asks for clarification on whether the capacitors are in parallel or series. The responder explains that the capacitors are in parallel and can be replaced with an equivalent capacitance. Finally, the conversation ends with a question about how to determine if capacitors are in parallel or series, to which the responder explains that they must be physically wired together to be in parallel.
  • #1
cupid.callin
1,132
1
Hi all,

This question was given in my physics book. Given that: C1 = 4uF and C2 = 6uF (u=micro) ... it comes out to be C1 + C2 = 10uF

I used the general method ... you know ... assign charges, assume potentials... solve equations.

My question is that aren't the two capacitors highlighted red in parallel, because i guess they are as the potential drop across them is same, but it doesn't work to get the answer i.e. 10uF.

If they are not in parallel, please tell me how to tell if two capacitors are in series or parallel ...

Thanks for help!
 

Attachments

  • 00978.jpg
    00978.jpg
    27 KB · Views: 470
Last edited:
Physics news on Phys.org
  • #2
All the C1s are paralleled by C2s as you spotted. There are four such parallel capacitor instances in the given circuit. They can each be replaced with an equivalent capacitance. This reduces the equivalent circuit to four capacitors, all of the same size. There will be two pairs of series-connected capacitors, which are in turn connected in parallel. The series connected pairs can each be reduced to single equivalent capacitors. Then you're left with these two single capacitors in parallel, so rinse, repeat. You're left with one equivalent capacitor.

The result, 10uF for the equivalent capacitance of the whole circuit, is correct.
 
  • #3
Oh yes,,, you are right!

I don't know what i was thinking while solving the ques. myself!
More sleep!

One more ques.
Two (or more) capacitors are in parallel if the potential drop across them is same ... Right? Or is there any other way to tell if two are in series or parallel ??!
 
  • #4
cupid.callin said:
Oh yes,,, you are right!

I don't know what i was thinking while solving the ques. myself!
More sleep!

One more ques.
Two (or more) capacitors are in parallel if the potential drop across them is same ... Right? Or is there any other way to tell if two are in series or parallel ??!

Component terminals need to be physically wired together (the same nodes in a circuit diagram) in order to be in parallel. Two capacitors charged to the same voltage but not connected are not in parallel.
 
  • #5
Thanks for your help gneill !
 

FAQ: Calculating Capacitance: Series vs Parallel

What is capacitance and why is it important?

Capacitance is the ability of a system to store electrical energy. It is an important concept in understanding and designing electronic circuits, as it affects the performance and behavior of many components.

What is the difference between series and parallel capacitance?

In series capacitance, multiple capacitors are connected in a chain where the positive end of one capacitor is connected to the negative end of another. In parallel capacitance, multiple capacitors are connected side by side, with the positive ends connected together and the negative ends connected together.

How do you calculate the total capacitance of a series circuit?

In a series circuit, the total capacitance is equal to the reciprocal of the sum of the reciprocals of each individual capacitor's capacitance. This can be represented mathematically as: C(total) = 1 / (1/C1 + 1/C2 + 1/C3 + ...)

How do you calculate the total capacitance of a parallel circuit?

In a parallel circuit, the total capacitance is equal to the sum of the individual capacitances. This can be represented mathematically as: C(total) = C1 + C2 + C3 + ...

When should I use a series or parallel circuit for capacitors?

Series circuits are typically used when you want to increase the overall capacitance while keeping the voltage constant. Parallel circuits are used when you want to increase the voltage while keeping the overall capacitance constant. It ultimately depends on the specific needs and goals of your circuit.

Similar threads

Why Capacitors in Parallels vs. Series: Coaxial Capacitor Case
Replies
2
Views
1K
Capacitors in series or in parallel? - calculating CR
Replies
8
Views
2K
Capacitors in Parallel: Finding the Relationship Between Capacitance and Charge
Replies
6
Views
2K
Capacitors in Series and Parallel
Replies
1
Views
3K
Find the equivalent capacitance of the circuit
Replies
12
Views
2K
Analyzing a circuit with multiple batteries
Replies
15
Views
2K
Find the maximum potential difference across a series circuit
Replies
11
Views
4K
What is the value of capacitance C?
Replies
3
Views
4K
Capacitors charged in parallel
Replies
3
Views
2K
Capacitance in a Complicated Mixed Circuit
Replies
19
Views
2K

Hot Threads

Recent Insights

Back
Top