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Which among the following lamps has the maximum burning hours?
LED.
Incandescent.
Metal halide.
Compact fluorescent.
LED.
Light Emitting Diodes (LEDs) possess the longest operational lifespan among common lighting technologies, typically ranging from 25,000 to 50,000 hours or more. Unlike traditional bulbs that rely on filament combustion or gas discharge, LEDs use solid-state electroluminescence, which significantly reduces physical wear.
Light Emitting Diodes (LEDs) possess the longest operational lifespan among common lighting technologies, typically ranging from 25,000 to 50,000 hours or more. Unlike traditional bulbs that rely on filament combustion or gas discharge, LEDs use solid-state electroluminescence, which significantly reduces physical wear.
P=VтЛЕI тАФ Electrical power consumption of an LED
╬╖=P╬жтАЛ тАФ Luminous efficacy, where ╬ж is luminous flux and P is power
LEDs function through electroluminescence in a semiconductor p-n junction. When forward-biased, electrons from the n-type region recombine with holes in the p-type region, releasing energy in the form of photons. Because there is no fragile filament or fragile glass vacuum seal, the device is highly durable and exhibits minimal thermal degradation.
LEDs are solid-state lighting devices with no moving parts or filaments.
Lifespan is usually defined by 'L70', the time taken for light output to drop to 70% of its initial value.
They operate at lower temperatures compared to incandescent or metal halide lamps.
High luminous efficacy results in lower energy consumption for the same light output.
Extremely long service life
High energy efficiency (high lumens per watt)
Instantaneous switching (no warm-up time)
Directional light emission
Higher initial capital cost compared to incandescent lamps
Sensitive to high ambient temperatures (requires heat sinking)
Non-linear dimming requirements
Street and architectural lighting
Residential and industrial illumination
Automotive headlamps and indicators
Display screen backlighting
| Feature | LED | Incandescent |
|---|---|---|
Avg. Life (Hours) | 25,000 - 50,000+ | 750 - 2,000 |
Incandescent lamps (Option B) have the shortest lifespan due to the evaporation of the tungsten filament.
Metal Halide (Option C) lamps are high-intensity discharge lamps with good efficacy but significantly shorter lives than LEDs.
CFLs (Option D) have a lifespan of approximately 8,000-15,000 hours, limited by electrode degradation and electronic ballast failure.
A is correct тАФ LED technology utilizes solid-state semiconductor physics, allowing for a operational lifespan significantly exceeding that of traditional thermal or gas-discharge lamps.
Always remember that for illumination questions, 'efficacy' relates to energy efficiency, while 'burning hours' relates to the physical durability and material degradation of the light source.