Recording power and lumens for light bulbs.

[pebbles]

Homework Statement

Which is more efficient, or has the highest lm/W, a lower- or higher-power light bulb? To find out, look at bulbs and record the power and lumens.

Homework Equations

Lumen, lm, = P or luminous flux.

The Attempt at a Solution

Power of the light bulbs would be the number of watts, correct?
I am confused as to how to calculate the lumens of a light bulb. My teacher said that we can just look at bulb boxes at a store, so I know no measuring of surfaces is involved.


Thanks in advance.

 

[kamerling]

In europe, the number of Lumen will be present on the box.
I Have 2 boxes here that say:
230 V, 60 W, 710 Lumen
230 V, 100 W, 1340 Lumen
Kind of bulb: "Pearl"
so I don't think there is any calculation involved. I'd try to get some more datapoints