why are incandescent light bulbs considered to be lower efficiency than led bulbs

Question

a smaller amount of energy is wasted by the incandescent bulb

a smaller percentage of the energy output of the LED bulb toward light

a greater amount of energy is required for the same light output from the LED bulb

a greater percentage of the energy output of the incandescent bulb goes toward heat

Answer 1

Incandescent light bulbs are considered to be lower efficiency than LED bulbs primarily because a greater percentage of the energy output of the incandescent bulb goes toward heat.

To elaborate:

• Incandescent bulbs produce light by heating a metal filament until it glows, which means a significant portion of the energy (about 90%) is converted into heat rather than visible light. This results in a very low luminous efficacy (light output per watt of energy consumed).

• LED bulbs, on the other hand, produce light by electroluminescence, which is much more efficient. They convert a much higher percentage of energy directly into light (often around 80-90% of their energy use goes toward light output).

Therefore, the correct statement about why incandescent bulbs are lower in efficiency compared to LED bulbs is: a greater percentage of the energy output of the incandescent bulb goes toward heat.