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Light Emmiting Diodes
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Which among the following is most energy efficient incandescent build fluorescent tube compact fluorescent light bulb halogen bulb?
Incandescent produces about 10 lumens of light per watt of electricity Halogen produces about 13 lumens per watt Fluorescent and CFL produce about 50 lumens per watt So Fluorescent is the most efficient.
What is measured in lumens?
Lumens is a measure of light flux, so is independent of the area. It is essentially the amount of light available. So think of a bright light. It has a fixed amount of lumens, regardless of how near or far you are. Lux is the light level at a surface. If you think of a light bulb, the lux will vary with the distance from the light source because the light spreads out. 1 lux = 1 lumen per sq meter. Most light meters read out in lux, which is a measure of the brightness at a surface. You will measure more luxes when you are closer to the bulb, than when farther away. Suppose you are measuring a compact flourescent lightbulb (CFL), which is roughly cylindrical in shape. You use your light meter and read 1000 foot-candles at about 1/2" from the lightbulb. How do you compute the lumens of the lightbulb? (1) Convert the foot-candles to lux: 1000 foot-candles = 10764 lux (2) Compute the area over which that lux value applies. This is roughly a cylinder that is 1/2 inch bigger in all directions from the bulb. So measure the bulb. We are going to convert all of our measurements into metric units. 1/2 inch = 0.0127 meters bulb height = 9 cm or 0.09 m bulb radius = 2 cm or 0.02 m inflated height = h = 0.09 m + 2 * 0.0127 m = 0.1154 m inflated radius = r = 0.02 m + 0.0127 m = 0.0327 m area_of_cylinder = 2*pi*r*(r+h) = 2 * 3.14 * 0.0327 *(0.0327 + 0.1154) = 0.03 m^2 (3) Compute the total lumens of the bulb: bulb_lumens = 10764 lux * 0.03 m^2 = 327.5 lumens. Notes: a) If your bulb is more like a sphere, you should use the formula for the surface area of a sphere rather than a cylinder. b) When measuring the lux or foot-candles of the bulb, you should measure at several locations and average the number. c) If you measure from a large distance away from the bulb, then you can ignore the size of the bulb in your calculations.
How many lumens for an led replacement vs stock 1141 bulb?
A lumen is a measure of how much total light a bulb produces. Incandescent (1156) bulbs spray their light through almost 360 degrees and lamp housings designed for them rely on that. Most LED lamps put all their light out in a narrow cone and work poorly with standard 1156 housings. However, there are LED assemblies that have their light-producing chips arranged around a sphere and they work well in standard housings. The LEDs you see on commercial vehicles are mounted in housings designed for their narrow cone output, that's why they look bright. A standard 1156 bulb puts out about 400 lumens when new. As of January 2010, I haven't found an LED replacement that puts out any more, and most are only 50 lumens or so, not enough for a standard 1156 housing. To confirm the above: From Bosch Automotive Handbook7th ed. a 1156 (BA15S) Stop/Turn 21W bulb puts out 460 lumens. For a 5W Side marker / Tail BA15S it is 50 lumens (strangely low, I know) and 10W Tail light 125 lumens. If replacing with a warm white LED, then that is how many lumens you need to match the brightness (as well as light direction being good). BUT, if using a Red LED for a brake light or an Amber LED for Turn signals, then less lumens are needed. This is because the Red lens of a brake light filters out all the blue, yellow, green, etc out of white light, but filters nothing from a Red LED. The question now is: What is the percentage of "Red" in the light output of a "White" incandescent bulb?
How many lumen's does a 200 watt light bulb produce?
100 W tungsten incandescent (220 V): 1380 lm
How much Oxygen is produced by average plant per day?
The amount of oxygen is proportional to the light they receive. Most plants produce around one cubic centimeter of oxygen for every ten lumens of light absorbed.
How many lumens per watt?
161 lumens I believe the above answer to be inaccurate. It depends on the light source. For example: For an incandescent light bulb 1 watt it is approx. 18 Lumens. However most LED's use only about 10% the wattage to produce the same amount of light. So for LED's .1 watt produces 18 Lumens.
What is lumens per watt could you give a brief definition about lumens per watt?
Luminous efficacy is a figure of merit for light sources. It is the ratio of luminous flux (in lumens) to power (usually measured in watts). As most commonly used, it is the ratio of luminous flux emitted from a light source to the electric power consumed by the source, and thus describes how well the source provides visible light from a given amount of electricity.This is also referred to as luminous efficacy of a source.
What is the source of most light energy on earth?
The Sun. It gives off light 1st of all because it's the sun, but also it gives light to solar panel powered buildings or homes.
Which among the following is most energy efficient incandescent build fluorescent tube compact fluorescent light bulb halogen bulb?
Incandescent produces about 10 lumens of light per watt of electricity Halogen produces about 13 lumens per watt Fluorescent and CFL produce about 50 lumens per watt So Fluorescent is the most efficient.
What are light bulbs that don't save energy are called?
All light bulbs use energy. Incandescents produce 10 lumens per watt, halogens about 13 lumens per watt, fluorescents and LEDs 40-50 lumens per watt. Lumens measure the brightness, watts measure the speed at which electrical energy is used. So the ones which use the most energy are called incandescent and then halogen.
Why is led most important source of light?
LED is not the most important source of light, the Sun is.
Is bioluminescence is earth most important source of light?
bioluminescence is earths most important source of light tru or false
What is the lumen output of a 30W LED flood light?
Generally lumen is a measure of the total amount visible light form a lamp or light source. LEDs are about the same as CFLs, producing about 50 lumens per watt, compared to 10 lumens for incandescent bulbs or 13 lumens for halogen.
What is measured in lumens?
Lumens is a measure of light flux, so is independent of the area. It is essentially the amount of light available. So think of a bright light. It has a fixed amount of lumens, regardless of how near or far you are. Lux is the light level at a surface. If you think of a light bulb, the lux will vary with the distance from the light source because the light spreads out. 1 lux = 1 lumen per sq meter. Most light meters read out in lux, which is a measure of the brightness at a surface. You will measure more luxes when you are closer to the bulb, than when farther away. Suppose you are measuring a compact flourescent lightbulb (CFL), which is roughly cylindrical in shape. You use your light meter and read 1000 foot-candles at about 1/2" from the lightbulb. How do you compute the lumens of the lightbulb? (1) Convert the foot-candles to lux: 1000 foot-candles = 10764 lux (2) Compute the area over which that lux value applies. This is roughly a cylinder that is 1/2 inch bigger in all directions from the bulb. So measure the bulb. We are going to convert all of our measurements into metric units. 1/2 inch = 0.0127 meters bulb height = 9 cm or 0.09 m bulb radius = 2 cm or 0.02 m inflated height = h = 0.09 m + 2 * 0.0127 m = 0.1154 m inflated radius = r = 0.02 m + 0.0127 m = 0.0327 m area_of_cylinder = 2*pi*r*(r+h) = 2 * 3.14 * 0.0327 *(0.0327 + 0.1154) = 0.03 m^2 (3) Compute the total lumens of the bulb: bulb_lumens = 10764 lux * 0.03 m^2 = 327.5 lumens. Notes: a) If your bulb is more like a sphere, you should use the formula for the surface area of a sphere rather than a cylinder. b) When measuring the lux or foot-candles of the bulb, you should measure at several locations and average the number. c) If you measure from a large distance away from the bulb, then you can ignore the size of the bulb in your calculations.
What is the most powerful light?
The most powerful source of light is gamma-rays and the most weakest is radio.
What is the definition for Luminous and non luminous?
"Luminous" means emitting light (conveniently measured in units known as Lumens). Synonym would most often be "glowing".
What is the most common light source?
the sun
