The IEC defines DC voltages between 0 and 120 volts as which category?

The IEC defines DC voltages between 0 and 120 volts as which category?

• A. low voltage
• B. extra-low voltage
• C. extra safe
• D. none of these

Answer: (B)

Extra-low voltage is the category for DC voltages from 0 to 120 V. The IEC classifies voltages to guide safety requirements, and for DC the threshold is 120 V—voltages up to this point are considered extra-low, meaning the shock hazard is comparatively lower and protection can be less stringent than for higher voltage ranges. This includes common control-system and battery voltages like 12 V, 24 V, and up to 120 V DC. Voltages above 120 V DC fall into the low-voltage category, which carries stricter safety requirements. The option “extra safe” isn’t a standard IEC category, and “none of these” is incorrect because there is a defined category for this range.

Extra-low voltage is the category for DC voltages from 0 to 120 V. The IEC classifies voltages to guide safety requirements, and for DC the threshold is 120 V—voltages up to this point are considered extra-low, meaning the shock hazard is comparatively lower and protection can be less stringent than for higher voltage ranges. This includes common control-system and battery voltages like 12 V, 24 V, and up to 120 V DC. Voltages above 120 V DC fall into the low-voltage category, which carries stricter safety requirements. The option “extra safe” isn’t a standard IEC category, and “none of these” is incorrect because there is a defined category for this range.