# Calculating the current in an inductor (AC)

• scizzzro
In summary, both individuals obtained the same result of 3.52 for the current at 0.4 seconds when integrating the given equation. However, there is a discussion on whether or not units should be included in the answer. One person believes it is important to include units, while the other suggests that a number without units is acceptable for this question. Including units in the answer is considered a good practice in engineering fields.
scizzzro
Homework Statement
A 100mH inductor is connected directly to a voltage source whose voltage is given by
v = 0V for t<0s
and
v = 5(1-e^(-t)) V for T =>0s

The inductor current at t=0 s is zero. Calculate the inductor current at t=0.4 s
Relevant Equations
v = 5(1-e^(-t))
I integrated the second equation given in the form (integral)di= 1/L * (integral) V *dt and I got an answer of 3.52 for the current at 0.4 seconds, anyone can let me know if this is correct?

I get the same result. Should you include units with your answer?

scizzzro
TSny said:
I get the same result. Should you include units with your answer?

Thanks, it says for just a number for inductor current without units just for this question

TSny
scizzzro said:
Thanks, it says for just a number for inductor current without units just for this question
Yes, but the information you used to get the solution did have units (V, mH, sec), so when you calculated the answer, it also gets units. Maybe your grader doesn't care, but they are there, and should be included IMO. This is a really good habit to develop in any engineering field.

TSny

## 1. What is an inductor?

An inductor is an electrical component that stores energy in the form of a magnetic field. It is typically made of a coiled wire and is used in circuits to control the flow of current.

## 2. How do you calculate the current in an inductor?

The current in an inductor can be calculated using the formula I = V / XL, where I is the current in amps, V is the voltage in volts, and XL is the inductive reactance in ohms. Inductive reactance is calculated using the formula XL = 2πfL, where f is the frequency in hertz and L is the inductance in henrys.

## 3. What is the difference between AC and DC current?

AC (alternating current) is a type of current that changes direction periodically, while DC (direct current) flows in only one direction. AC is commonly used in household electricity, while DC is used in batteries and electronic devices.

## 4. How does inductance affect the current in a circuit?

Inductance affects the current in a circuit by resisting changes in the flow of current. When the current in an inductor changes, it creates a back EMF (electromotive force) that opposes the change. This can cause the current to lag behind the voltage in an AC circuit.

## 5. What are the applications of inductors?

Inductors are commonly used in electronic circuits to filter out unwanted frequencies, store energy, and control current flow. They are also used in power supplies, motors, transformers, and many other electrical devices.

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