What are the two causes of \"flicker\"?

What are the two causes of \"flicker\"?

• A. Dirty power and a bad globe
• B. Low voltage and high voltage
• C. Harmonics and power factor
• D. Temperature and humidity

Answer: (A)

Flicker happens when the light output rapidly changes over short periods. The two most direct causes are dirty power and a bad globe. Dirty power means the electrical supply itself isn’t stable—voltage swings, noise, or harmonics from other equipment can cause the lamp to brighten and dim quickly. A bad globe means the lamp or its electronics is failing to react smoothly to the supplied voltage, so even with a stable source the light can flutter. Other factors like low versus high voltage can cause dimming or brightness shifts, but they aren’t as consistently linked to rapid, irregular flicker. Harmonics and power factor describe overall power quality, not the specific, quick brightness fluctuations flicker represents. Temperature and humidity can affect equipment, but they’re not the typical root causes of flicker in lighting.

Flicker happens when the light output rapidly changes over short periods. The two most direct causes are dirty power and a bad globe. Dirty power means the electrical supply itself isn’t stable—voltage swings, noise, or harmonics from other equipment can cause the lamp to brighten and dim quickly. A bad globe means the lamp or its electronics is failing to react smoothly to the supplied voltage, so even with a stable source the light can flutter.

Other factors like low versus high voltage can cause dimming or brightness shifts, but they aren’t as consistently linked to rapid, irregular flicker. Harmonics and power factor describe overall power quality, not the specific, quick brightness fluctuations flicker represents. Temperature and humidity can affect equipment, but they’re not the typical root causes of flicker in lighting.