The amplitude of the effective current is:
Correct answer: A. Irms cos θ
- A. Irms cos θ
- B. Irms sin θ
- C. Io cosθ
- D. Infinity
Explanation
The correct option is (Irms), which stands for the root mean square current. In an AC circuit, this value represents the effective or average current. It's calculated as the square root of the average of the squared values of the current over one complete cycle. This measure is useful because it reflects the equivalent steady DC current that would produce the same heating effect in a resistor as the AC current in question.
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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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