Which statement is true about flicker causes?

Which statement is true about flicker causes?

• A. Dirty power or a bad globe can cause flicker
• B. Flicker is caused only by color temperature changes
• C. Flicker is not related to power quality
• D. Flicker occurs only in LED drivers

Answer: (A)

Flicker shows up as rapid changes in light output, usually driven by instability in the electrical supply or the lighting device’s control electronics. Dirty power—voltage sags, surges, transients, or harmonic distortion—causes the lamp to continually draw varying current, so brightness dips and rises quickly, which we notice as flicker. A bad globe can also flicker because a defective bulb may not maintain a steady electrical current or light emission, especially as it ages or if the internal components are failing. The other statements don’t fit: color temperature changes relate to the color of the light, not the rapid brightness fluctuation that defines flicker; flicker is indeed related to power quality; and flicker isn’t limited to LED drivers—any lamp with unstable power or faulty drivers can flicker.

Flicker shows up as rapid changes in light output, usually driven by instability in the electrical supply or the lighting device’s control electronics. Dirty power—voltage sags, surges, transients, or harmonic distortion—causes the lamp to continually draw varying current, so brightness dips and rises quickly, which we notice as flicker. A bad globe can also flicker because a defective bulb may not maintain a steady electrical current or light emission, especially as it ages or if the internal components are failing.

The other statements don’t fit: color temperature changes relate to the color of the light, not the rapid brightness fluctuation that defines flicker; flicker is indeed related to power quality; and flicker isn’t limited to LED drivers—any lamp with unstable power or faulty drivers can flicker.