What is a light bulb watt?

Question

what is the definition of watt and how do they determine how many watts are in a light bulb?

Answer 1

It is how much power the bulb uses at its rated voltage.  For example a 115V / 100W bulb draws 0.87 Amps (A = W/E = 100W/115V).

How does this relate to light output? This varies depending on the bulb technology. Incandescent bulbs convert the vast majority of their input power to heat. See link below for more details.

Answer 2

A watt is one joule per second.

It is a rate that energy is being dissipated or generated.

Watts are not "in" a bulb. A 100 watt bulb uses energy at the rate of 100 joules per second. It was designed so that if it is connected to a 120 volt line (240 in europe) it will use that amount of power and glow brightly.

.

Answer 3

check out

www.thefreedictionary.com/watt

It tells you what it means.