Is there anything other than Resistance, Capacitance, Inductance in a circuit? [closed]

Question

Resistance, Capacitance and Inductance measure certain electrical property of some matter. These term have even given rise to objects like resistors, capacitors and inductors respectively.

Few multiple questions I have is:

1. Does it make sense to ask questions like "what is the resistance of this capacitor" or "What is the capacitance of this resistor" etc.

2. How do we know that resistors, capacitors and inductors are the only basic building block of circuits. What prevents something entirely new quantity like W to exist which encapsulates certain new property to be found?

P.S.Consider the situation. I place a object and pass current through it and now want to analyses the situation. In reality it would be extremely complicated but we can proceed it by making a series of correction. So first I will assume it has some internal resistance and then correct for it. Next my friend come and suggest to factor in the capacitance of the object to get a more accurate picture. Then next I will also include the inductance effect of the object to get even more accurate picture. So I want to know when this series of correction will end. Undergrad circuit theory class suggest that I only need to look at only 3 entities i.e. resistor, capacitor and inductors to correct the circuit. But I am unconvinced by it and hence the question.

Answer 1

Capacitors, resistors and inductors are idealized elements. Every inductor has some resistance associated with it in real life, as well as some capacitance, and every capacitor possess some (small) amount of inductance and resistance, etc.

For accuracy, these second-order effects (called "stray capacitance", "parasitic inductance" and so on) must be included in the circuit analysis to obtain the right answers.

Here are some other circuit elements to include in your list:

1. the amplifier, which possesses gain

2. the gyrator, in which a flow of current as an input signal produces a force as the output variable (example: a permanent magnet DC motor)

3. the transformer which scales voltage and current in the input to a new voltage and current combination in the output, while conserving energy.

Answer 2

Resistance, Capacitance and Inductance measure certain electrical property of some matter. These term have even given rise to objects like resistors, capacitors and inductors respectively.

They measure certain electrical properties of circuits.

1. Does it make sense to ask questions like "what is the resistance of this capacitor" or "What is the capacitance of this resistor" etc.

Yes, because every circuit has resistance, capacitance, and inductance even if they don't contain resistors, capacitors, or inductors.

2. How do we know that resistors, capacitors and inductors are the only basic building block of circuits. What prevents something entirely new quantity like W to exist which encapsulates certain new property to be found?

Based on present knowledge, the only passive electrical characteristics of electric circuits are resistance, capacitance, and inductance. But they are not the only basic building blocks of a circuit. There are also active circuit elements like voltage sources and transistors, as well as passive semiconductor elements like diodes that together build an electric circuit.

But even these other active and passive devices all have resistance, capacitance and inductance characteristics when they are in a circuit. The degree to which each of the characteristics effect the performance of the device in the circuit depends primarily on the rate of change of the currents and voltages in the circuit. That's because, for an ideal capacitor and inductor,

$$i_{C}(t)=C\frac{dv(t)}{dt}$$ and $$v_{L}(t)=L\frac{di(t)}{dt}$$

which means voltages and currents are dependent on frequency, whereas for an ideal resistor,

$$i(t)=\frac{v(t}{R}$$

with $R$ being independent of frequency.

Hope this helps.