Given a sinusoidal current with a frequency of 50 Hz and an RMS value of 30 A, which of the following expressions correctly describes this waveform?

Explanation

The RMS current (I_rms) relates to the peak current (I_peak) in a sinusoidal wave by I_peak = I_rms × √2. Here, I_rms = 30 A, so I_peak = 30 × 1.414 ≈ 42.42 A. The angular frequency ω = 2πf = 2 × 3.1416 × 50 ≈ 314 rad/s. Thus, the correct waveform expression is I(t) = 42.42 sin(314 t).