What is meant by the efficiency of a lamp?

Question

What is meant by the efficiency of a lamp?

Answer 1

It's the amount of light it produces for the energy it consumes. You will usually find the light output in lumens listed on the package. Divide that number by the energy consumption in watts and you have efficiency in lumens per watt.

Answer 2

efficiency is always output by input.

Hoiw much energy it gives in terms of light energy.Bulbs gives only 15% light.

Flourcent tubes about 40% compact  flourcent lamps gives about 80 percent and new Leds may be still better

Answer 3

It's how much energy it uses compared to how much light it produces.