The statement that a 20W lamp produces as much light as a regular 100W lamp seems unusual and contradictory. In general, the wattage of a lamp is an indication of its power consumption and not necessarily directly related to the amount of light it produces.
Typically, the higher the wattage of a lamp, the more electrical power it consumes, which results in more light output. In traditional incandescent bulbs, for example, a higher wattage generally corresponds to a brighter light.
However, with advancements in lighting technology, such as the development of energy-efficient bulbs like LEDs (Light Emitting Diodes), it has become possible to achieve higher levels of brightness with lower wattages. LED bulbs are known for their energy efficiency, producing more light output per watt compared to traditional incandescent bulbs. For instance, a 20W LED bulb can produce the same amount of light as a 100W incandescent bulb.
The increased efficiency of LED bulbs is primarily due to their ability to convert a larger percentage of electrical energy into visible light while minimizing wasted heat. LED technology utilizes semiconductors that emit light when an electric current passes through them. This allows them to produce more lumens (a measure of brightness) per watt compared to older lighting technologies.
Therefore, if someone claims that a 20W lamp produces as much light as a regular 100W lamp, it is likely they are referring to the efficiency of LED technology, where a lower-wattage LED bulb can provide a comparable amount of light output to a higher-wattage incandescent bulb.