All Questions
Tagged with radiation visible-light
42
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How to measure light intensity in a room?
Does anyone know how I would go about measuring the light intensity in a room? I'm not interested in knowing the lux reading, I would like to measure the $W/m^2$ due to thermal radiation in my ...
- 31
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Absorption and emission spectrum
I was wondering how do you see a spectrum when light is passed through a substance. Like most of the substances we use are opaque, so how does light pass through them without being reflected? Also ...
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Diffrence between thermionic emission and photoelectric emission
Thermionic emission involves heat energy to excite the electron and remove it. In the photoelectric effect, a beam of light is involved.
As per my understanding heat and photons, both are energy. Heat ...
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1
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291
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Radiation pressure at a oblique surface
I am doing a problem that asks the radiation pressure of a beam of light on a oblique surface. The problem says: A laser beam of intensity I reflects from a flat, totally reflecting surface of area A, ...
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1
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What range of light on the electromagnetic spectrum are produced by the de-excitation of electrons?
When an electron moves from an excited state to its ground state, a photon is emitted, which is the source of light. However, I know that the highest energy form of light, gamma rays, are produced ...
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How to find the energy of white light? [duplicate]
If we have a single frequency of light, then the energy associated with that light ray can be given as:
$$ E = h \nu$$
However, white light is a mixture of different frequencies of light in 'some' ...
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2
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What is black-body equivalent of UV part of solar spectrum?
If all non-UV light was filtered from sunlight, does this approximate a different type of black body radiation? Regular sunlight has a black-body temperature of 5777 K.
This is in relation to the ...
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-1
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2
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2k
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Is there anything that can produce light without UV rays?
I've read that everything from fire to LEDs can produce UV radiation. Generally, unless intended otherwise, lightbulbs will have a phosphor coating to prevent UV radiation from escaping the bulb. ...
- 233
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How much potential energy is in a tritium glowstick?
I have a small tritium key chain light I got for my birthday. It will glow for decades, so I thought it would be fun to try to figure out how bright it is in lumens, and how much energy is stored in ...
- 1,406
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Why does the polarization type ($s$ or $p$) of electromagnetic waves effect the reflectivity and reflectivity of the light differently
So the Fresnel equations can describe the reflectivity and transmission of $s$ and $p$ polarized light and show that there is a different relationship between angle of incidence and the power ...
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16
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6
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Why can I see the top of objects in a reflection when they are not facing the reflective surface?
Why am I able to see the top of the pictures even though they aren’t facing the reflexive surface.
The light would have to travel down through the picture
- 502
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Why does light not propagate backward in dense media?
It is easy to see how light propagating in a dense medium destructively interferes laterally and constructively interferes in the forward direction. This is why light will travel forward in such a ...
- 1,581
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139
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Understanding radiation of objects
I am trying to understand Greenhouse effect. I have heard that during the day the earth absorbs heat from the sun in the form of visible light, and during the night it looses heat in the form of ...
- 127
4
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3
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755
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Can radiation light up a fluorescent light?
Watching the excellent but horrific HBO Miniseries Chernobyl.
There is a scene where the radiation level is so strong, it ruins the batteries of flashlights being operated inside the plant, in the ...
- 141
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Light from an incandescent lamp [duplicate]
In a tungsten filament lamp, electrons travel through a high resistance path,due to which the temperature is increased.
Now why does it emit light , is it because of the transitions of electrons from ...
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