An alternating current in ampere varies with time to second as $I = 4 \sin (200 \pi t)$. the frequency of current is:
Correct answer: A. 100 Hz
- A. 100 Hz
- B. 200 Hz
- C. 400 Hz
- D. 800 Hz
Explanation
The given expression for the alternating current is I = 4 sin(200πt), where the angular frequency ω is 200π. The relationship between angular frequency ω and frequency f is expressed as ω = 2πf. Therefore, we can solve for f:ω = 2πf200π = 2πff = 200π / 2π = 100 HzThus, the frequency of the current is 100 Hz. The other options are incorrect due to misinterpretations of the relationship between angular frequency and frequency.
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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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