Capacitors in series questions

The voltage across the first capacitor in this series of 3 capacitors can be found by applying the voltage divider rule:V_1 = \frac{C_2}{C_1+C_2+C_3}V_{total}In summary, the conversation was about finding the voltage, charge, and equivalent capacitance in a series circuit of three capacitors, with the speaker expressing frustration with their professor and textbook. The equivalent capacitance can be calculated using the expression for a series circuit, and the voltage across the first capacitor can be found using the voltage divider rule. Additionally, the charge in all capacitors is the same and is related to voltage and capacitance by the equation q = CV.
  • #1
ulfric
1
0
Good day everyone. Please help with these questions.

The circuit is a series of 3 capacitors with a battery.
C1 = C
C2 = 2C
C3 = 3C

How do you find the voltage across the first capacitor in a series of 3?

How do you find the charge Q on the first capacitor?

How do you find the equivalent capacitance Ceq for this combination of capacitors in series?

I had these questions on a test and know the answers but not how to arrive at them. I am usually quick on the uptake but teaching this basic stuff adequately is apparently beneath my professor and the text is terrible! (stay away from Young & Geller!)

Thanks for any help you can provide.
 
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  • #2
The equivalent capacitance of a series of n capacitors is done by the expression:
[tex]\frac{1}{C_{eq}}=\sum_{k=1}^n \frac{1}{C_k}[/tex]
The charge in all capacitors is the same.
Charge, voltage and capacitance are related by:
[tex]q = CV[/tex]
 
  • #3


Hello there,

First of all, it's great that you are seeking help and trying to understand these concepts better. I can assure you that learning the fundamentals is crucial for success in any scientific field.

To answer your questions, let's start with the basics. In a series circuit, the voltage across each component is the same. This means that the voltage across the first capacitor (C1) will be the same as the voltage across the second (C2) and third (C3) capacitors. So, to find the voltage across C1, you can simply measure the voltage across any of the capacitors in the series circuit.

Next, to find the charge (Q) on the first capacitor, we can use the formula Q = CV, where C is the capacitance and V is the voltage. Since we know the capacitance of C1 (C), we can simply multiply it by the voltage across C1 to find the charge on it.

Finally, to find the equivalent capacitance (Ceq) for the series combination of capacitors, we can use the formula 1/Ceq = 1/C1 + 1/C2 + 1/C3. In this case, since all the capacitors have different values, we need to first find the reciprocal of each capacitance (1/C1, 1/C2, 1/C3), add them together, and then take the reciprocal of the sum to get the equivalent capacitance.

I hope this helps. If you have any further questions, don't hesitate to ask. Remember, it's important to fully understand the basics before moving on to more complex concepts. Good luck with your studies!
 

Related to Capacitors in series questions

1. What is the formula for calculating the total capacitance of capacitors in series?

The total capacitance (C) of capacitors in series can be calculated using the formula: 1/C = 1/C1 + 1/C2 + 1/C3 + ... where C1, C2, C3, etc. are the individual capacitances of each capacitor.

2. How do capacitors in series affect the overall voltage in a circuit?

When capacitors are connected in series, the overall voltage (V) in the circuit is divided across each capacitor according to their individual capacitances. The total voltage across the capacitors will be equal to the sum of the voltages across each capacitor.

3. Can capacitors in series have different capacitance values?

Yes, capacitors in series can have different capacitance values. However, the overall capacitance will be less than the smallest individual capacitance, as the formula for calculating total capacitance involves adding the reciprocals of the individual capacitances.

4. What happens to the total capacitance when capacitors in series are added in parallel?

When capacitors in series are added in parallel, the total capacitance increases as the individual capacitances are added together. The total capacitance can be calculated using the formula: C = C1 + C2 + C3 + ...

5. How do capacitors in series affect the overall energy storage in a circuit?

Capacitors in series do not affect the overall energy storage in a circuit, as the total energy stored in a capacitor is dependent on its individual capacitance and the voltage across it, which remain the same regardless of how the capacitors are connected.

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