What is the formula to find Imax from Irms?

What is the formula to find Imax from Irms?

• A. Imax = Irms / .707
• B. Imax = Irms × .707
• C. Imax = Irms
• D. Imax = Irms / 1.414

Answer: (A)

For a sinusoidal current, the RMS value is the peak value divided by the square root of 2. In equation form, Irms = Imax / sqrt(2). To get the peak current from the RMS value, you multiply by sqrt(2), which is the same as dividing by 0.707 (since 1/0.707 ≈ 1.414). So the correct expression is Imax = Irms / 0.707, which is equivalent to Imax = Irms × sqrt(2) ≈ Irms × 1.414. The other forms don’t match the sine-wave relationship: dividing by 1.414 would give a result about 0.707 of Irms, and multiplying by 0.707 also yields a smaller peak value; using Irms alone assumes a situation (like DC) where peak equals RMS, not a sine wave.

For a sinusoidal current, the RMS value is the peak value divided by the square root of 2. In equation form, Irms = Imax / sqrt(2). To get the peak current from the RMS value, you multiply by sqrt(2), which is the same as dividing by 0.707 (since 1/0.707 ≈ 1.414). So the correct expression is Imax = Irms / 0.707, which is equivalent to Imax = Irms × sqrt(2) ≈ Irms × 1.414. The other forms don’t match the sine-wave relationship: dividing by 1.414 would give a result about 0.707 of Irms, and multiplying by 0.707 also yields a smaller peak value; using Irms alone assumes a situation (like DC) where peak equals RMS, not a sine wave.