Standards of power quality include the following:

• A. Power factor
• B. Surge protection
• C. Harmonics
• D. Any of these

Answer: (D)

Power quality standards cover several aspects of how electrical systems perform and protect equipment. Power factor relates to how efficiently the current is used; keeping a good power factor reduces wasted current, lowers losses, and helps maintain voltage quality. Surge protection focuses on guarding equipment against transient overvoltages from lightning, switching, or faults, with standards guiding appropriate devices and coordination to limit damage. Harmonics arise from nonlinear loads that distort the incoming waveform, which can cause overheating, trips, and interference; standards set limits on harmonic content to keep systems clean and reliable. Because standards may address any of these elements, the correct idea is that any of these can be included in power quality standards.