Phase Differences in of voltage in RC and LR circuits

In summary, the voltage in an RC circuit is leading the capacitor voltage by 90° because voltage is directly proportional to the integral of current in a capacitor. In an LC circuit, the resistor voltage is lagging the inductor voltage by 90° because voltage is proportional to the derivative of current in an inductor. This can be seen in the equations for purely resistive, purely inductive, and purely capacitive circuits, where the phase difference is represented by CosΘ and SinΘ. However, understanding the concept behind alternating circuits may require some knowledge of math.
  • #1
Nadun
4
0
Hey guys can someone please give me a good explanation on why in an RC circuit the resistor voltage is leading the capacitor voltage by 90°. While in an LC circuit the resistor voltage is lagging the inductor voltage by 90°.
Thanks
 
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  • #2
You are talking about an AC circuit where the voltage is given by the equation V= V0sinωt. (ω= Angular frequency). Represent the current in similar terms and derive respective equations for a purely resistive, purely inductive and purely capacitive circuits. Then compare the phase difference.

Hint: CosΘ and SinΘ has a phase difference of 90 degrees.
 
  • #3
hmm do you think you could explain it to me in physical terms, cos mathematically seems really confusing
 
  • #4
Do you want me to explain you the concept behind alternating circuits?
 
  • #5
I understand the basics of AC, and the concept of reactance, and what a capacitor does and what an inductor does to AC current i just don't get why one leads the other
 
  • #6
Hhhhmmm...I am not sure I can leave math out of the question and explain in pure english...

The way I see it, in a capacitor, voltage is directly proportional to charge and charge is the accumulation (integral) of current; so, voltage is proportional to the integral of current.

In an inductor, voltage is produce only when the current changes, i.e., voltage is proportional to the derivative of the current.

Without bringing explicit equations into the mix...does this help?
 

What is a phase difference in RC and LR circuits?

A phase difference in RC and LR circuits refers to the difference in the timing or alignment of the voltage and current waveforms in these types of circuits. It is measured in degrees and can indicate the relationship between the two signals.

How is phase difference calculated in RC and LR circuits?

The phase difference in RC and LR circuits can be calculated using trigonometric functions such as sine, cosine, and tangent. It can also be determined by comparing the time delay between the peak of the voltage and current waveforms in the circuit.

What causes phase difference in RC and LR circuits?

Phase difference in RC and LR circuits is caused by the reactive components in the circuit, such as capacitors in RC circuits and inductors in LR circuits. These components can cause a time delay between the voltage and current signals, resulting in a phase difference.

How does phase difference affect the performance of RC and LR circuits?

The phase difference in RC and LR circuits can affect the overall performance of the circuit by changing the impedance and power factor. It can also affect the frequency response and stability of the circuit.

What are some practical applications of phase difference in RC and LR circuits?

Phase difference in RC and LR circuits is important in many practical applications, such as power transmission and distribution systems, audio and video signal processing, and electronic filters. It is also used in the design and analysis of electronic circuits to optimize their performance.

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