Question
What is reactance?
Answer Options
- A) Opposition to the flow of direct current caused by resistance
- B) Opposition to the flow of alternating current caused by capacitance or inductance
- C) Reinforcement of the flow of direct current caused by resistance
- D) Reinforcement of the flow of alternating current caused by capacitance or inductance
Correct Answer: B
Explanation
Reactance is the electrical opposition offered by an inductor (L) or a capacitor (C) to the flow of alternating current (AC). It is similar to resistance, but unlike resistance, reactance does not dissipate energy as heat; instead, it stores energy in an electric or magnetic field and returns it to the circuit.
Reactance is designated by the letter X and is measured in ohms, just like resistance. Inductive reactance (X_L) increases with frequency, while capacitive reactance (X_C) decreases with frequency. The combination of resistance and reactance constitutes the circuit’s total impedance (Z).
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