IEM Flashcards
a device that is used to change the magnitude of electric current and potential into higher and lower values.
Transformer
Transformer applies the principle of
mutual induction
Transformer will operate only with a
changing electric current (AC)
Usually composed of wires wrapped around in an iron core and consists of
primary and secondary coils
The change in the voltage is ______ to the ratio of the number of turns (windings) in the secondary coil (Ns) to the number of turns in the primary coil (Np).
directly proportional (tranformer law)
The change in current across a transformer is in the ______ from the voltage change but in the ______.
opposite direction
same proportion
transformer with a turns ratio greater than 1
Step up transformer
Increases the voltage but decreases the current.
Step up tranformer
a transformer with turns ratio less than 1
Step down transformer
Decreases the voltage but increases the current.
Step down transformer
is made from a single primary winding wrapped around a laminated magnetic core, and operates on the principle of self-induction.
Autotransformer
tapped at various points along its length to provide a percentage of the primary voltage supply across its secondary load.
Single winding
is a device that stores electric charges producing a potential difference (static voltage) across its plates, much like a small rechargeable battery.
Capacitor
consists of two or more parallel conductive (metal) plates that are electrically separated either by air or insulating material.
Capacitor
The insulating material between plates is called
dielectric
