What device is used to reduce high voltages and currents to safe values for measurements?

The use of instrument transformers is essential for ensuring safe and accurate measurements in high-voltage environments. These devices, which include both current transformers (CTs) and voltage transformers (VTs), work by converting high voltages or currents into lower, more manageable levels that can be safely measured by standard measuring instruments.

Current transformers achieve this by producing a scaled-down current that is proportional to the actual high current flowing in the circuit. Similarly, voltage transformers step down high voltages to a level appropriate for measurement. This transformation process not only protects measuring instruments from damage due to excessive voltage or current but also allows for safe operations and accurate readings in electrical systems where high power levels are present.

Other options, such as capacitors and resistors, play different roles in electrical circuits. A capacitor stores electrical energy, while a resistor primarily limits current flow or drops voltage based on Ohm's law. A voltage divider is a configuration of resistors used to produce a lower voltage from a higher voltage, but it does not inherently provide the safety and scaling that instrument transformers do. Thus, instrument transformers are specifically designed for high-voltage applications to mitigate risks and facilitate accurate assessments.