The ripple-free DC voltage limit for extra low voltage is?

The correct understanding of the ripple-free DC voltage limit for extra low voltage is grounded in standards that define safety and operational parameters for electrical systems. The extra low voltage (ELV) limit is intended to minimize the risk of electric shock and ensure safety for users and equipment.

According to various electrical safety standards, the threshold for extra low voltage is set at a maximum of 120 volts. This limit ensures that voltages remain low enough to pose a reduced risk of hazardous conditions so that when experienced by a human, it is unlikely to cause injury or serious harm. Therefore, recognizing 120 volts as the upper limit for ripple-free DC voltages aligns with these safety standards and demonstrates an understanding of key electrical concepts pertinent to safe design and implementation practices in various applications.

The choices that exceed 120 volts do not align with the established guidelines for extra low voltage, reinforcing why the understanding of this limit is critical for electrical inspection and testing qualifications.