Question

An individual white LED (light-emitting diode) has an efficiency of 20% and uses 1.0 W of electric power. a. How many LEDs must be combined into one light source to give a total of 1.6 W of visible-light output (comparable to the light output of a 40 W incandescent bulb)? b. What total power is necessary to run this LED light source?

Answer 1

8, 8 W

Step-by-step explanation:

The useful power of 1 Light Emitting Diode is

`0.2* 1=0.2\ W`

Total power required is 1.6 W

Number of Light Emitting Diodes would be

`n=(1.6)/(0.2)\\\Rightarrow n=8`

The number of Light Emitting Diodes is 8.

Power would be

`P=8* 1=8\ W`

The power that is required to run the Light Emitting Diodes is 8 W