8.11.2: Induced Voltage and Electrical Generators
- Page ID
- 476705
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Learning Objectives
- Describe how an electric generator produceds an electric current.
We started this section by saying that most of the power that we use comes to us either from a battery or a generator. But previously we stated that there were many sources of energy: fossil fuels, wind, hydroelectric, and others. How can both of these be true at the same time? The reality is that every power plant relies on a generator.
In our discussion on electromagnetic induction, we learned that it was possible to create an electrical charge by spinning a wire through a magnetic field. We also learned that the more loops of wire, the greater the charge of the induced electricity, but also the harder it is to move the wire through the magnetic field. If it was possible to find an energy source that could move the loop of wire through the magnetic field we would be able to transform that kinetic energy into electrical energy. This is essentially what is done with our power sources. wind and hydroelectric power use a turbine to convert the movement of the requisite fluid into rotational energy which can then rotate loops of wire through a magnetic field in order to create an electric current. For fossil fuels, biomass, or nuclear power the production of heat is used to cause high pressure steam to move against a turbine to produce similar results.
One thing to note with the function of a generator is that as the wire loop moves through the magnetic field, the current generated will fluctuate. At the points where the electric current is parallel to the magnetic field, the generated current will be zero. At the points where the direction of the electric current is perpendicular to the magnetic field, the generated current will be the strongest. But also, the current will change the direction that it flows in from one maxima to the next. This is different than the type of current that flows from a battery, and the contrast between them will be discussed in greater detail in the next subsection.
Section Summary
- The movement of an electric wire through a magnetic field will result in an electric current, and can provide a sustained electric current if there is a way to sustain the movement of the electric wire.
- Various energy sources are able to power electric generators.
- Electric generators result in a current whose flow fluctuates as the wire loops move through the magnetic field.
Glossary
- generator
- a device that produces electric current by turning an electric wire through a magnetic field.
- turbine
- a device that converts the kinetic energy of a flowing fluid into rotational energy.
- electromagnetic induction
- the process of inducing a voltage with a change in magnetic flux