SI The unit of impedance
Correct answer: D. Ohm
- A. Hertz
- B. Henry
- C. Volt
- D. Ohm
Explanation
The correct option, "ohm (Ω)," represents the unit of impedance. Impedance is the total opposition that a circuit offers to the flow of alternating current (AC), encompassing both resistance (which opposes the flow of current in a resistor) and reactance (which arises from the effects of inductance and capacitance in the circuit). In electrical circuits, impedance is analogous to resistance in direct current (DC) circuits but takes into account the frequency-dependent effects of inductors and capacitors in AC circuits. Impedance is measured in ohms (Ω), just like resistance, and it quantifies the overall opposition to the flow of AC current in the circuit.
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About Alternating Current
Alternating current varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
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