The instantaneous current in a circuit is given by I = √2 sin(ωt + ∅) ampere what is the rms value of the current?
Correct answer: C. 1 A
- A. 2 A
- B. √2 A
- C. 1 A
- D. (1/√2)A
Explanation
The RMS (Root Mean Square) value of a sinusoidal alternating current is given by dividing the peak current by √2. For the given current I = √2 sin(ωt + ∅) A, the peak current I0 is √2 A. Thus, the RMS current is IRMS = I0/√2 = √2/√2 = 1 A. Therefore, the correct answer is 1 A. The other options are incorrect because they either represent the peak current or a miscalculated RMS value.
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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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