How many lumen in 5w lamp?

Answer 1

Those are two different units for two different measurements; a lumen is used to determine luminosity (brightness), and watts are a unit for measuring how much current is passing through an object.

Answer 2

Lumens is a measure of light output previously Candela and now (unless someones come up with a new name) Lux. Light transmitted from an electric light will depend on the type of bulb, filament lights are inneficient giving off a lot of heat instead of light and the new energy efficient lamps give off more light per watt than the filament bulbs. Unfortunately with the energy efficient lamp you don't get the full spectrum of light so things look a different colour than in daylight.

In factory lighting they used to mix Mercury vapourlamps (blue light) with sodium lamps(yellow light) to balance things out.

Answer 3

"Watt" is the rate at which the lighting device uses energy. "Lumens" is the

amount of light it's able to produce from that steady stream of energy.

Different technologies produce different amounts of light while using

energy at the same rate. That's why a compact fluorescent lamp (CFL)

uses less power and costs less to operate than an incandescent bulb,

although it produces the same amount of light.

Answer 4

The ratio of lumens to watts is termed the 'efficacy' (note, this is not the same thing as 'efficiency') of a lamp. The efficacy of a lamp depends on the type of lamp: for example, incandescent lamps have low values of efficacy, whereas others, such as fluorescent lamps have much higher values. You need to check the internet to determine the efficacy for the type of lamp you have in mind.

Answer 5

It depends on the efficacy (not 'efficiency'!) of the lamp, as it varies considerable according to whether the lamp is incandescent, fluorescent, etc.

Answer 6

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