Capacitor in parallel with resistor

In summary, there is a circuit with an effective resistor and capacitor in parallel. The capacitors are uncharged, causing all the current to flow through them instead of the resistors. This results in zero voltage drop across the capacitors and zero current through the resistors. However, the total voltage drop should be the same as the voltage of the battery, causing confusion. The battery provides a voltage to both the resistor and capacitor, theoretically giving them the same potential. Kirchoff's law says the potential should be 24V, but other analysis suggests 0V. The introduction of a battery at the end adds further confusion, as the initial setup involved two capacitors and two resistors.
  • #1
galoisien
6
0
(another problem but less differential equations-sy)


Consider a circuit where there is an effective resistor in parallel with an effective capacitor.

Each effective capacitor consists of two capacitors in series, same for the resistor.

Now, when the capacitors are uncharged, all the current is flowing through the capacitors and not through the resistors.

However, since the capacitors are uncharged, the voltage drop across them is zero. Since there is no current through the resistors, the current through them is also zero.



But the total voltage drop must be the voltage drop of the battery! Yet I seem to be getting zero!
 
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  • #2
galoisien said:
(another problem but less differential equations-sy)


Consider a circuit where there is an effective resistor in parallel with an effective capacitor.

Each effective capacitor consists of two capacitors in series, same for the resistor.

Now, when the capacitors are uncharged, all the current is flowing through the capacitors and not through the resistors.

However, since the capacitors are uncharged, the voltage drop across them is zero. Since there is no current through the resistors, the current through them is also zero.



But the total voltage drop must be the voltage drop of the battery! Yet I seem to be getting zero!

Could you please describe the circuit in better detail? At first there are two caps in parallel with two resistors, but at the very end you introduce a battery? Where is the battery?
 
  • #3
Sorry the battery provides a voltage E (i.e. 24V) to both the effective resistor and capacitor -- i.e. theoretically both the resistor and capacitor should have the same potential.

Kirchoff's law says it should be 24V, but other analysis says 0V. I am confused.

(also the two-resistor, two-capacitor thing was to allow an analysis of comparing the potentials of0 point between the two resistors and the point between the two capacitors).
 

What is a capacitor in parallel with a resistor?

A capacitor in parallel with a resistor is a circuit configuration where the capacitor and resistor are connected to the same two nodes, or points, in a circuit. This means that they share the same voltage and are connected in parallel to the same source.

What is the purpose of connecting a capacitor in parallel with a resistor?

The purpose of connecting a capacitor in parallel with a resistor is to create a low-pass filter. This means that the circuit will allow low-frequency signals to pass through while blocking high-frequency signals. This can be useful in smoothing out signals or reducing noise in a circuit.

What are the effects of adding a capacitor in parallel with a resistor?

The addition of a capacitor in parallel with a resistor will affect the overall impedance, or resistance, of the circuit. It will also change the phase relationship between the voltage and current in the circuit. Additionally, it will create a time delay in the charging and discharging of the capacitor.

What is the formula for calculating the total impedance of a circuit with a capacitor in parallel with a resistor?

The formula for calculating the total impedance of a circuit with a capacitor in parallel with a resistor is Z = √(R² + (1/ωC)²), where R is the resistance in ohms, ω is the frequency in radians per second, and C is the capacitance in farads.

How does the capacitance value affect the behavior of a circuit with a capacitor in parallel with a resistor?

The capacitance value of the capacitor in parallel with a resistor will affect the cutoff frequency and bandwidth of the circuit. A higher capacitance value will result in a lower cutoff frequency and a wider bandwidth, allowing more frequencies to pass through the circuit. On the other hand, a lower capacitance value will result in a higher cutoff frequency and a narrower bandwidth, allowing fewer frequencies to pass through the circuit.

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