The current in a series RL circuit

In summary, the conversation discusses the calculation of resistance in a series RL circuit based on the given information of current increase and inductance. The equation I=I_0(1-e^(-t/(L/R))) is mentioned but its accuracy is uncertain. The final value and value after 3.4μs are also discussed.
  • #1
BryceHarper
15
0

Homework Statement



The current in a series RL circuit increases to 20% of its final value in 3.4μs. If L = 2.0mH, what is the resistance R?

Homework Equations



I=I_0(1-e^(-t/(L/R))) <----Im not sure if this equation is right?


The Attempt at a Solution



I'm unsure how to start this problem, or if I'm on the right track with this equation?
 
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  • #2
BryceHarper said:
The current in a series RL circuit increases to 20% of its final value in 3.4μs. If L = 2.0mH, what is the resistance R?
I=I_0(1-e^(-t/(L/R))) <----Im not sure if this equation is right?
Neither do I, but assuming it is...
In terms of the variables in that equation, what would be the final value, and what would be the value after 3.4μs?
 

1. What is a series RL circuit?

A series RL circuit is an electrical circuit that consists of a resistor (R) and an inductor (L) connected in series with a power source. The current in this type of circuit flows through both components in a single loop.

2. What is the role of the inductor in a series RL circuit?

The inductor in a series RL circuit stores energy in the form of a magnetic field. As the current flows through the inductor, the magnetic field builds up and resists any changes in the current flow. This property of inductors is what causes a delay in the current in a series RL circuit.

3. How does the current behave in a series RL circuit?

In a series RL circuit, the current will initially be low due to the inductor's resistance to changes in current. As the inductor's magnetic field builds up, the current will gradually increase until it reaches a steady state. At this point, the current will be determined by the resistance of the circuit and the voltage of the power source.

4. What is the equation for calculating the current in a series RL circuit?

The equation for calculating the current in a series RL circuit is I = V/R, where I is the current, V is the voltage of the power source, and R is the total resistance of the circuit. This equation assumes that the inductor has reached a steady state and the current is constant.

5. How does the current change if the resistance or inductance in a series RL circuit is increased?

If the resistance in a series RL circuit is increased, the current will decrease as the overall resistance in the circuit increases. On the other hand, if the inductance is increased, the current will decrease initially due to the inductor's resistance, but then it will gradually increase to reach a steady state with a higher current value.

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