In the formula F = (S × P) ÷ 120, what does 'S' stand for?

In the formula F = (S × P) ÷ 120, 'S' represents the speed of rotation in RPM (Revolutions Per Minute). This formula is used in electrical engineering to calculate the frequency (F) of an AC motor based on its rotational speed and power rating.

By multiplying the speed of rotation (S) in RPM by the power rating (P), you can determine how many cycles per second (Hertz) the motor produces, which is then adjusted by dividing by 120 to convert the value into the correct frequency units. This relationship is essential for understanding how motor speed affects electrical frequency in systems like alternating current (AC) motors.

The context of the options further emphasizes that in this particular formula, while the power rating, system voltage, and power factor are indeed critical aspects of electrical systems, they do not represent the variable 'S' specifically. Instead, they serve different roles in the equations related to power consumption and efficiency. Thus, understanding 'S' as speed is crucial for mastering this calculation.