Understanding First Order Circuits: DC vs. AC

In summary, the solution for this practice problem includes parallel components and the current is only calculated across the resistors. This may seem backwards as the inductor is expected to be a short circuit to DC, but it is actually modeling the inductor charging up. This is evident through the given voltage and the fact that some current must be flowing through the inductor due to Kirchhoff's Current Law. Therefore, the inductor is not shorting out.
  • #1
edsys89
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Hi, I'm confused with the solution given for this practice problem.
All of these components are said to be in parallel, yet the current is worked out only across the resistors. I thought the inductor would be a short circuit to DC.
Am I looking at this backwards, is it modelling the inductor charging up?
 

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  • #2
edsys89 said:
Hi, I'm confused with the solution given for this practice problem.
All of these components are said to be in parallel, yet the current is worked out only across the resistors. I thought the inductor would be a short circuit to DC.
Am I looking at this backwards, is it modelling the inductor charging up?

The sole fact that are you given Vo(t) = 2V implies that there must be current running through the other branch of resistance because there is voltage across it. (They are in parallel) Since this current isn't identical to the current in the other resistor branch, by KCL some of it must be flowing through the inductor.

This is enough to conclude that it's not being shorted out by the inductor.
 
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Related to Understanding First Order Circuits: DC vs. AC

1. What is the main difference between DC and AC circuits?

The main difference between DC (direct current) and AC (alternating current) circuits is the direction in which the current flows. In a DC circuit, the current flows in one direction, while in an AC circuit, the current changes direction periodically.

2. How do the components differ in a DC vs. AC circuit?

The components in a DC circuit, such as resistors, capacitors, and inductors, behave the same way regardless of the direction of current flow. In an AC circuit, the components may have different properties when the current changes direction, such as reactance in capacitors and inductors.

3. What is the role of frequency in AC circuits?

The frequency of an AC circuit refers to the rate at which the current changes direction. It is measured in Hertz (Hz). The frequency affects the behavior of components in an AC circuit, as well as the overall power and efficiency of the circuit.

4. How do you analyze a first order circuit?

To analyze a first order circuit, you must use Kirchhoff's circuit laws and apply basic circuit analysis techniques, such as Ohm's law and the voltage and current divider rules. You will also need to understand the behavior of components in both DC and AC circuits.

5. What are some real-world applications of first order circuits?

First order circuits are commonly used in electronic devices, power supplies, and communication systems. They are also used in residential and commercial buildings for lighting and electrical distribution. Additionally, first order circuits are used in industrial applications for machinery control and power management.

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