Circuit/Mechanical oscillator analogy

In summary, the conversation discusses the analogy between an RLC circuit and a damped harmonic oscillator. The inductor serves as the inertia and removing it results in oscillations with an infinite frequency and immediate decay of amplitude. The poster's initial guess is that without the inductor, the capacitor will discharge exponentially to zero.
  • #1
jdstokes
523
1

Homework Statement



I've been pondering the analogy between an RLC circuit and a damped harmonic oscillator.

The inductor serves the role of the inertia, leading a finite charging frequency.

What happens if we remove the inductor, so that the system consists just of a charged capacitor, with each plate connected by a wire of resistance R?

The Attempt at a Solution



The mathematics suggests that the system will undergo oscillations with an effectively infinite frequency and that the amplitude will instantly decay to zero.

This doesn't seem to make sense. What would really happen?
 
Physics news on Phys.org
  • #2
For anyone interested, my initial guess is rubbish: with no inductor, there is no interchange between energy stored by the magnetic and electric fields, so the charged capacitor simply discharges exponentially to zero.
 
  • #3


I would like to address the question of what would really happen if we removed the inductor from the RLC circuit analogy. First, it is important to understand the purpose of the inductor in the circuit and its role in creating oscillations. The inductor stores energy in its magnetic field and resists changes in current, leading to the characteristic frequency and damping in the circuit.

If we were to remove the inductor, the system would no longer have a means to store energy and resist changes in current. This would result in a lack of oscillations and the current would simply flow through the circuit without any changes or decay. In other words, the system would behave more like a simple resistor-capacitor circuit.

However, this does not necessarily mean that the amplitude would instantly decay to zero. There may still be some small fluctuations in the current due to the capacitor's ability to store energy. The exact behavior of the system would depend on the specific values of resistance and capacitance in the circuit.

In summary, removing the inductor from the RLC circuit would result in a different behavior of the system, but it is not accurate to say that the amplitude would instantly decay to zero. It is important to consider the role of each component in the circuit and how their removal would affect the overall behavior.
 

1. What is the circuit/mechanical oscillator analogy?

The circuit/mechanical oscillator analogy is a comparison between the behavior of a mechanical oscillator, such as a pendulum, and an electrical circuit. Just as a pendulum oscillates back and forth due to the conservation of energy, an electrical circuit with a capacitor and inductor can also oscillate between energy storage in the capacitor and inductor.

2. How are mass and inertia represented in the analogy?

In the analogy, mass is represented by the inductance of the circuit, while inertia is represented by the capacitance. This is because inductors resist changes in current, similar to how mass resists changes in velocity, and capacitors resist changes in voltage, similar to how inertia resists changes in position.

3. What is the relationship between frequency and resonant frequency in the analogy?

In the analogy, frequency is analogous to the rate of oscillation of a mechanical oscillator, while resonant frequency is the frequency at which the circuit reaches maximum amplitude. This is similar to how a mechanical oscillator reaches maximum amplitude at its natural frequency.

4. How does damping factor affect the circuit/mechanical oscillator analogy?

In the analogy, damping factor represents the amount of energy dissipated in the circuit or mechanical oscillator. A higher damping factor results in a quicker dissipation of energy and a smaller amplitude of oscillation, while a lower damping factor results in a longer period of oscillation and a larger amplitude.

5. What are some practical applications of the circuit/mechanical oscillator analogy?

The circuit/mechanical oscillator analogy has many practical applications in fields such as electrical engineering, mechanical engineering, and physics. It can be used to design and analyze electrical circuits, model mechanical systems, and understand the behavior of oscillating systems in general. It is also the basis for technologies such as radio frequency oscillators, electronic filters, and vibration analysis tools.

Similar threads

  • Introductory Physics Homework Help
Replies
2
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
717
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Classical Physics
Replies
4
Views
779
  • Introductory Physics Homework Help
Replies
10
Views
2K
  • Classical Physics
4
Replies
131
Views
4K
  • Atomic and Condensed Matter
Replies
14
Views
2K
  • Introductory Physics Homework Help
Replies
10
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
12K
  • Introductory Physics Homework Help
Replies
2
Views
2K
Back
Top