# How Do You Calculate Current Amplitude in a Parallel RC Circuit?

• nateastle
In summary: Z the same way with the capaicitor and reisitor in parrallel?No. The voltages are the same across R and C and the total current is the sum of the R and C currents (except there is a 90 degree phase difference between the two currents, of course). It is similar to parallel circuits with only resistance.
nateastle
A resistor with a resistance of 500 ohms and a capacitor with with a capacitance of 2 x 10^-6 f are connected in parrallel to an ac generator that supplies an rms voltage of 260 v at an angular frequency of 377 rad /s find the current amplitude in the resistor (Ir)peak.

I know I have to convert 377 from rad / s to hz when I do I get 60 hz. From there I am unsure of how to calculate the rest. I know in a traditional series lrc circuit you calculate Z = [(Xl -Xc)^2 + R^2]^.5 but I and with z you can find the i which would be V/Z.

nateastle said:
A resistor with a resistance of 500 ohms and a capacitor with with a capacitance of 2 x 10^-6 f are connected in parrallel to an ac generator that supplies an rms voltage of 260 v at an angular frequency of 377 rad /s find the current amplitude in the resistor (Ir)peak.

I know I have to convert 377 from rad / s to hz when I do I get 60 hz. From there I am unsure of how to calculate the rest. I know in a traditional series lrc circuit you calculate Z = [(Xl -Xc)^2 + R^2]^.5 but I and with z you can find the i which would be V/Z.
Since V is the rms voltage then I = V/Z is the rms current. The peak voltage is $\sqrt{2}V_{rms}$ So peak current is $V_{peak}/Z$

AM

would you calculate Z the same way with the capaicitor and reisitor in parrallel?

nateastle said:
would you calculate Z the same way with the capaicitor and reisitor in parrallel?
No. The voltages are the same across R and C and the total current is the sum of the R and C currents (except there is a 90 degree phase difference between the two currents, of course). It is similar to parallel circuits with only resistance.

$$V_R = V_C = V; I_R = V/R; I_C = V/X_C$$

$$I_R + I_C = I = V/Z = V/R + V/X_C$$ so:

$$\frac{1}{Z} = \frac{1}{R} + \frac{1}{X_c} = \frac{1}{R} + j\omega C}$$

AM

Last edited:

## 1. What is amplitude in a resistor?

Amplitude in a resistor refers to the maximum voltage or current that can be measured across the resistor. It is also known as the peak value or magnitude of the signal passing through the resistor.

## 2. How is amplitude related to resistance?

There is no direct relationship between amplitude and resistance. However, the amplitude of the signal passing through a resistor can be affected by its resistance. A higher resistance will result in a lower amplitude signal, while a lower resistance will result in a higher amplitude signal.

## 3. Can amplitude in a resistor be negative?

Yes, the amplitude in a resistor can be negative. This can occur when the AC signal passing through the resistor is inverted or when the resistor is part of a complex circuit with multiple components.

## 4. How is amplitude measured in a resistor?

Amplitude in a resistor can be measured using a voltmeter or an oscilloscope. The voltmeter measures the voltage across the resistor, while the oscilloscope measures the amplitude of the AC signal passing through the resistor.

## 5. How does amplitude affect the functionality of a resistor?

The amplitude of the signal passing through a resistor does not affect its functionality. A resistor's function is to limit the flow of current in a circuit, and this is determined by its resistance value, not the amplitude of the signal passing through it.

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