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The temperature of the object.
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Why does planck curve decline after reaching the peak wavelength?
A blackbody can only emit a finite amount of power, so the curve better decline. In other words the integral from nu = 0 to nu=positive infinity had better be finite.
If the inner accretion disk around a black hole has a temperature of 1000000 K at what wavelength will it radiate the most energy?
For a thermal radiation source, the peak of the blackbody radiation curve is at a photon energy 2.8 times the temperature in electron-volts. The temperature in electron-volts is 1/11,600 times the temperature in Kelvin. Use E = hv to convert from the photon energy (E) to photon frequency, using Plank's constant h. Use v = c/(lambda) to convert from the photon frequency to the wavelength. The result: these hot plasmas radiate X-rays, and the peak wavelength is about 50 Angstroms, i.e. 5 nm.
What are the characteristics of the spectrum of the cosmic background radiation?
The measurements at a number of discrete frequencies of the background radiation that fills space place their relative amplitudes reasonably close to the curve that characterizes the radiation of a blackbody with a temperature of 2.725 degrees absolute. As such, the peak amplitude is found at the frequency of about 162.5 GHz.
Why are there no purple stars?
Basically it has to do with the blackbody spectrum. Hot objects emit a broad spectrum of light, not just a single color. At the point where the temperature is such that the blackbody radiation peaks in the ultraviolet the overall spectrum is such that the emitted light appears to us as largely blue. There may well be purple stars, but from our eyes, they appear blue. Our eyes, slightly deceive us. See the related link for a picture of how our eyes perceive colour at a given temperature, and another for a video explaining in detail this question. Our Sun would appear a kind of peach, if we had eye's better developed to a blackbody spectrum Purple is a combination of blue and red. The light emitted by a star is of such a nature (black body radiation curve) that there is one predominate colour and lesser component of lower frequencies. (Higher frequencies are rapidly attenuated.) It is therefore impossible to get two colour emission peaks in both the blue and red of equal intensity - consequently no purple stars. However you could have two stars closely orbiting each other: one blue and the other a red super giant, that at a great distance would look like a purple star, or a red star with a super hot white dwarf, that would work too. Interesting to note, the star Algol might fulfill this combination.
Why do you use the wavelength with the maximum absorbance in spectroscopy?
Short answer:Using the maximum wavelength gives us the best results. This is because at the peak absorbance, the absobance strength of light will be at the highest and rate of change in absorbance with wavelength will be the smallest. Measurements made at the peak absorbance will have the smallest error.Long answer: It really depends on what is the largest source of error. Taking the readings at the peak maximum is best at low absorbance, because it gives the best signal-to-noise ratio, which improves the precision of measurement. If the dominant source of noise is photon noise, the precision of absorbance measurement is theoretically best when the absorbance is near 1.0. So if the peak absorbance is below 1.0, then using the peak wavelength is best, but if the peak absorbance is well above 1.0, you might be better off using another wavelength where the absorbance is closer to 1. Another issue is calibration curve non-linearity, which can result in curve-fitting errors. The non-linearity caused by polychromatic light is minimized if you take readings at either a peak maximum or a minimum, because the absorbance change with wavelength is the smallest at those wavelengths. On the other hand, using the maximum increases the calibration curve non-linearity caused by stray light. Very high absorbances cause two problems: the precision of measurement is poor because the transmitted intensity is so low, and the calibration curve linearity is poor due to stray light. The effect of stray light can be reduced by taking the readings at awavelength where the absorbance is lower or by using a non-linear calibration curve fitting technique. Finally, if spectral interferences are a problem, the best measurement wavelength may be the one that minimizes the relative contribution of spectral interferences (which may or may not be the peak maximum). In any case, don't forget: whatever wavelength you use, you have to use the exact same wavelength for all the standards and samples. See http://terpconnect.umd.edu/~toh/models/BeersLaw.htmlTom O'HaverProfessor Emeritus
Why does planck curve decline after reaching the peak wavelength?
A blackbody can only emit a finite amount of power, so the curve better decline. In other words the integral from nu = 0 to nu=positive infinity had better be finite.
The blackbody curve depends on what single property?
temperature
Why is it that the sun appears yellow?
That is about where the peak of its blackbody radiation curve is, as determined by the photosphere temperature.
In terms of its blackbody curve describe what happens as a red-hot glowing coal cools off?
As an object cools, then its peak will move to the left, ie lower frequency/longer wavelength (Wien's Law). The total area underneath will also decrease (Stefan's Law).
Why do hot star appear blue in color?
Because the peak of their blackbody curve is near blue in the spectrum, for the temperature of their photosphere.
Does strength curve relate to any exercise?
Yes, any movement at all relates to the strength curve.
What is strength curve?
Relates to any exercise, Analyzes the components of strength production, Has seven factors
If the inner accretion disk around a black hole has a temperature of 1000000 K at what wavelength will it radiate the most energy?
For a thermal radiation source, the peak of the blackbody radiation curve is at a photon energy 2.8 times the temperature in electron-volts. The temperature in electron-volts is 1/11,600 times the temperature in Kelvin. Use E = hv to convert from the photon energy (E) to photon frequency, using Plank's constant h. Use v = c/(lambda) to convert from the photon frequency to the wavelength. The result: these hot plasmas radiate X-rays, and the peak wavelength is about 50 Angstroms, i.e. 5 nm.
Draw a demand curve illustrating price inelastic demand and explain how the curve relates to the definition of price elasticity of demand?
A perfectly inelastic demand curve will be completely horizontal and means that consumers would any price for a particular good, which is almost impossible. The closer to being horizontal a demand curve is, the more inelastic the demand.
Is there any completely incoherent light?
It's not clear exactly what you mean by "completely incoherent." Blackbody radiation is given off at any angle and any phase, but the shape of the intensity/frequency curve is determined by the temperature; is that close enough to "completely incoherent"?
As the wavelength decreases what happens to wave diffraction?
As wavelength decreases the wave diffraction will decrease, so the curve formed will be less noticeable. The sharpness of the diffraction will decrease that you can see will lessen.
What is the most dominant color emitted by the sun?
Looking at the solar spectrum, the curve peak is around wavelength 0.45(microns) falling under the ultraviolet band. This ultraviolet band runs from 0.30 - 0.45. This curve then drops off rapidly and exponentially when under "air mass 0" conditions (outer space) in "air mass 1" conditions (the earths surface) the spectrum follows this curve, with intensity's reduced however as our atmosphere adsorbs some wavelengths better than others the curve tends to jump too and from the trend while still maintaining the exponential decline as seen under air mass 0 conditions. So in short ultraviolet I guess would be the sortest answer ^-^ -Jason MEng
