How can the frequency of electrical current be expressed?

The frequency of electrical current is fundamentally about how often the current oscillates or cycles within a particular time period. This is quantified in terms of Hertz (Hz), which defines the number of cycles per second. Alternately, it can also be expressed in terms of pulses per second (pps) or cycles per second (cps). All these terms encapsulate the same fundamental concept of frequency, making this choice correct.

In contrast, the other options relate to different electrical concepts. Volts per ampere defines electrical resistance (Ohm's Law), Joules per second indicates power, and Newtons per meter pertains to stiffness or elasticity rather than frequency. By understanding these terms, one can see how they distinctly categorize different aspects of electrical engineering and physics.