An A.C series circuit containing 4Ω resistance and 3Ω inductive reactance. The impedance of the circuit is______________?
Correct answer: B. 5Ω
- A. 1Ω
- B. 5Ω
- C. 7Ω
- D. 7Ω
Explanation
Resistance and inductive reactance are perpendicular components of impedance, so Z = √(R² + XL²) = √((4 ohms)² + (3 ohms)²) = √25 ohms² = 5 ohms. Directly adding them gives 7 ohms, which ignores their 90° phase difference. Also, options c and d are duplicated.
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About AC Through Resistor, Capacitor and Inductor
Alternating current through a resistor, capacitor and inductor involves phase relationships between voltage and current, reactance, impedance and energy transfer. A resistor keeps voltage and current in phase, while a capacitor and inductor produce opposite phase shifts, a distinction used in circuit diagrams and numerical calculations.
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