540 likes | 1.66k Views
Impedance. is the measure of the opposition that a circuit presents to the passage of a current when a voltage is applied. In quantitative terms, it is the complex ratio of the voltage to the current in an alternating current (AC) circuit.
E N D
Impedance is the measure of the opposition that a circuit presents to the passage of a current when a voltage is applied. In quantitative terms, it is the complex ratio of the voltage to the current in an alternating current (AC) circuit
Resistance affects flow of current by opposing the flow of electrons in a ckt Resistance
Coil with wire wound around it Opposes any change in current flow It can not prevent the current from rising or falling but it will OPPOSE any rise or fall Current in ac ckts is constantly changing any inductance in that ckt will oppose this change Inductance
Made of 2 plates of conducting material Constantly charged and discharged due to sine wave changes The polarity of the voltage across the capacitor will be opposite of the supply voltage Therefore it opposes the supply voltage and will result in a lower net voltage which cause the current to be lower Capacitance in A.C. Ckt
Capacitance affects the current in the ckt by opposing a change in voltage Capacitance cannot prevent the voltage from rising or falling but it will oppose the rise or fall Capacitance in A.C CKT
Impedance measure in ohms (Z) Inductive reactance in ohms (XL) Capacitance reactance in ohms (XC) Impedance includes Resistance Inductive Reactance Capacitive Reactance All measure in ohms Summary A.C Resistance
Ohms law now becomes Z is the total opposition to current flow in ac ckts measured in ohms Summary A.C Resistance