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0. Math Review31m
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  31m
1. Intro to Physics Units1h 29m
2. 1D Motion / Kinematics3h 56m
3. Vectors2h 43m
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5. Projectile Motion3h 6m
6. Intro to Forces (Dynamics)3h 22m
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18. Waves & Sound3h 40m
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20. Heat and Temperature3h 7m
21. Kinetic Theory of Ideal Gases1h 50m
22. The First Law of Thermodynamics1h 26m
23. The Second Law of Thermodynamics3h 11m
24. Electric Force & Field; Gauss' Law3h 42m
25. Electric Potential1h 51m
26. Capacitors & Dielectrics2h 2m
27. Resistors & DC Circuits3h 8m
28. Magnetic Fields and Forces2h 23m
29. Sources of Magnetic Field2h 30m
30. Induction and Inductance3h 38m
31. Alternating Current2h 37m
32. Electromagnetic Waves2h 14m
33. Geometric Optics2h 57m
34. Wave Optics1h 15m
35. Special Relativity2h 10m

31. Alternating Current

Inductors in AC Circuits

Physics

31. Alternating Current

Inductors in AC Circuits

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1:26 minutes

Problem 9b

Textbook Question

What is the inductance of an inductor whose reactance is 120 Ω at 80.0 Hz?

Verified step by step guidance

Understand the concept of inductive reactance, which is the opposition that an inductor presents to alternating current. It is given by the formula:

X = ω L

, where

X

is the reactance,

ω

is the angular frequency, and

L

is the inductance.

Calculate the angular frequency

ω

using the formula:

ω = 2 π f

, where

f

is the frequency. Substitute

f

with 80.0 Hz.

Substitute the given reactance value

X = 120

Ω and the calculated angular frequency

ω

into the reactance formula:

X = ω L

Rearrange the formula to solve for inductance

L

L = \frac{X}{ω}

Substitute the values of

X

and

ω

into the rearranged formula to find the inductance

L

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Inductive Reactance

Inductive reactance is the opposition that an inductor presents to alternating current, due to the magnetic field created around it. It is given by the formula X_L = 2πfL, where X_L is the reactance, f is the frequency, and L is the inductance. This concept is crucial for understanding how inductors behave in AC circuits.

Inductance

Inductance is a property of an electrical conductor that quantifies its ability to induce an electromotive force when the current flowing through it changes. It is measured in henries (H) and is a fundamental concept in electromagnetism, affecting how circuits respond to changes in current and voltage.

Frequency

Frequency refers to the number of cycles per second of an alternating current, measured in hertz (Hz). It is a key parameter in AC circuits, influencing the reactance of inductors and capacitors. Understanding frequency is essential for calculating reactance and determining the behavior of AC circuit components.