A capacitor is connected across an ac source that has voltage amplitude 60.0 V and frequency 80.0 Hz. What is the phase angle Φ for the source voltage relative to the current? Does the source voltage lag or lead the current?
Ch 31: Alternating Current
31장, 문제 2a
A sinusoidal current i = I cosωt has an rms value Irms = 2.10 A. What is the current amplitude?
검증된 단계별 안내1
Understand the relationship between the rms value and the amplitude of a sinusoidal current. The rms (root mean square) value is a measure of the effective value of a varying current, and for a sinusoidal current, it is related to the amplitude by the formula: I_rms = I_amplitude / sqrt(2).
Identify the given values in the problem. You are provided with the rms value of the current, I_rms = 2.10 A.
Use the formula to express the amplitude in terms of the rms value: I_amplitude = I_rms * sqrt(2).
Substitute the given rms value into the formula: I_amplitude = 2.10 A * sqrt(2).
Calculate the amplitude using the expression from the previous step. This will give you the current amplitude, which is the peak value of the sinusoidal current.

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
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주요 개념
질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.
RMS Value
The root mean square (RMS) value of a sinusoidal current is a measure of the effective value of the alternating current. It is calculated as the square root of the average of the squares of the instantaneous values over one cycle. For a sinusoidal waveform, the RMS value is I_rms = I_0/√2, where I_0 is the amplitude.
추천 영상:
가이드 코스
RMS Current and Voltage
Current Amplitude
Current amplitude, denoted as I_0, is the peak value of the sinusoidal current. It represents the maximum instantaneous value that the current reaches during its cycle. In the context of RMS calculations, the amplitude is crucial for determining the effective current value using the relationship I_rms = I_0/√2.
추천 영상:
가이드 코스
Intro to Current
Sinusoidal Waveform
A sinusoidal waveform is a mathematical curve that describes a smooth periodic oscillation. It is characterized by its amplitude, frequency, and phase. In electrical circuits, sinusoidal currents and voltages are common, and their analysis involves understanding these parameters to determine effective values like RMS and peak amplitude.
추천 영상:
가이드 코스
Superposition of Sinusoidal Wave Functions
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