aC Electrical Flashcards
Three forms of AC?
Square wave, triangle tooth, sine wave.
What is alternating current ?
A form of current electricity where the polarity of the source periodically changes
Describe square wave?
Polarity periodically changes but value does not
Describe triangle tooth?
Polarity periodically changes, value changed with straight line variation.
Describe sine wave?
Polarity periodically changes, value changes based on sine function
Generation of sine AC?
Created through the principle of electromagnetic induction.
Definition of electromagnetic induction?
The creation of an electrical potential in a conductor by passing that conductor through lines of magnetic flux
What’s the difference between magnetic induction and electromagnetic induction?
Magnetic induction used an actual magnet
Polarity if the potential is based on what two things?
The orientation of the lines of flux, the direction the conductor is cutting the lines of flux.
How is the polarity of the potential determined?
By the left hand rule.
What is the left hand rule?
Point first finger in the direction of the lines of flux, point thumb in direction of conductor movement, middle finger will point in the direction of current flow.
Two ways of increasing potential?
Increase the strength of the flux field being cut, increase the rate at which the lines of flux are being cut.
Ways to increase the strength of the flux field?
Increase current flow through the electromagnet
Increase the density of the lines of flux
Ways to increase the rate at which lines of flux are cut?
Increase the speed of the conductor
Increase the number of conductors cutting the flux
Advantages of AC over DC?
Much easier to generate large quantities of, much easier to change values without substantial power loss, much easier to transfer over long distances.