एक कैडेंला क्या हैं? Ek Candela kya hai? Luminous Intensity. Lumen kya hai

Описание: What is 1 Candela?

Well, candela is the unit of luminous intensity in s i method. The term candela is a latin word, which literally means candle in English. Before going deep into the topic, we must have a clear idea of two different quantities related to it. Luminous flux, and, Energy or power of light.

Since light is a form of energy. A beam of light contains a certain amount of energy in it. When you lit a bulb, it releases energy in the form of light. In each second, a constant amount of energy generated in the form of light. It may be of any specified amount. More energy means more intense light. A small portion of the light may pass through this one steradian solid angle.

Now consider a light source, which can generate light in frequency of 540 trillion heartz only. Human eyes are most sensitive to this frequency. Let us assume that, no other frequency emits from this source. Also, consider a 1 steradian solid angle, from the light source. Now, if this lamp blink for a second, a beam of light will emit through this solid angle. And if this beam carries a total energy of 1 by 683 joule in it. Then we called its luminous flux to be 1 lumen.

Thus 1 lumen is the amount of light energy, of frequency 540 trillion heartz, which carries energy of 1 by 683 Watt, contained in a one steradian solid angle.

If the amount of energy is 2 by 683 Watt, then it is 2 lumen. If it is 3 by 683 Watt, then the beam is of 3 lumen luminous flux. And so on.

If you want a different frequency in this definition, the amount of energy will differ.

Have you cleared it?

So, now, we can tell you, what 1 candela is?

If a light source is able to generate one lumen beam through each unit solid angle in all possible directions, then its luminous intensity is 1 Candela.

In this sense, a one candela lamp can generate light of 4 pi lumen. Since total solid angle around a sphere is 4 pi steradian.

So, what we have learned so far

Lumen is the unit of luminous flux. On the other hand candela is the unit of luminous intensity.

Lumen tells you the amount of energy that a beam of light carries. But candela tells you how much light a lamp can generate.

Lumen describes a property of a light beam. On the other side, candela is a property of a light source.

Lumen is candela times steradian. Hence, candela is Lumen per steradian.

More candela of a light source means more lumen of light it can generate.

A simple candle has a luminous intensity of roughly 1 Candela. It can generate light beams of 12.57 lumen in all possible direction.

An incandescent bulb of 25 watt power rating, has luminous intensity of about 15 candela. It can generate lights of 200 lumen in all directions.

A Compact Fluoroscence lamp of 25 watt power rating, has a luminous intensity of about 127 candela. And, it can produce light of 1600 lumen in all three dimensional space.

L E D lamp is more efficient in this category. A 25 watt L E D lamp generates light beam of 2400 lumen. And its luminous intensity is nearly 191 candela. The most efficient light generator we have so far.

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