Voltage describes electrical potential, the pressure that pushes charges through a circuit. Think of it like water pressure in a hose—the higher the pressure, the more it pushes water along. In circuits, voltage is the driving force that moves charges from one point to another. The actual flow of charge, or current, depends on this pushing force and the resistance in the path (I ≈ V / R). Grounding is just a reference point with zero volts and a safe return path, not the push itself. So voltage is the term that matches the description.

Measuring current without interrupting a circuit relies on sensing the magnetic effect of the current rather than breaking the path. A clamp meter does exactly that by snapping a jaw around a single conductor. Inside the clamp is a current transformer (for AC) or a Hall-effect sensor (for DC) that detects the magnetic field produced by the current and converts it into a readable display. Because the conductor passes through the clamp without being part of the circuit itself, you can measure live current without opening the circuit, which is safer and quicker for on-the-spot checks. Many clamp meters are optimized for AC current, and higher-end models can also measure DC current with Hall-effect sensing. Regular multimeters can measure current, but they typically require the meter to be placed in series with the load, meaning you must disconnect the circuit to insert the meter and break the path. An inverter or battery system isn’t a measurement tool; they’re power conversion/storage devices, not instruments for sensing current.

Metal-clad cable is a type of cable that has a metallic outer sheath around insulated conductors, giving mechanical protection and often a grounding path. This is what defines MC cable, distinguishing it from other options. The thermoplastic-insulated wire refers to individual conductors, not a full cable with a metal jacket. Armored cable describes a different construction with armor around conductors and usually a separate jacket. Fiber-optic cable carries light signals and contains no electrical conductors. So, the correct classification for MC cable is metal-clad cable.

The rotor in an induction motor is driven by electromagnetic induction from the stator. When the stator windings are energized with AC, they create a rotating magnetic field. This rotating field passes through the air gap and cuts across the rotor conductors, inducing currents in the rotor according to Faraday’s law. Those rotor currents generate their own magnetic field, which interacts with the stator field to produce torque and spin the rotor. The rotor isn’t powered externally and doesn’t rely on permanent magnets, and friction isn’t what drives it. The slip between the rotor speed and the rotating field keeps induction and torque flowing.