Experimental determination of Stefan's constant

In summary, the conversation discusses the use of an apparatus to determine Stefan's constant through the use of an incandescent lamp and photovoltaic cell. The formula used is Stefan's constant = 2.43 x 10^-4 (Vs'/T), resulting in joules per square meter per second per quad Kelvin. The variables used are Vs' = Vo + Vs in volts, where Vo corresponds to the work function of the photo cathode and Vs corresponds to the maximum kinetic energy of photo electrons, which is related to the maximum energy of photons emitted by a black body at temperature T Kelvin. The minimum work function (Vo) can be obtained from the intercept on the Y-axis of a graph of Vs (mV) and
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Homework Statement


I am using an apparatus to determine Stefan's constant using incandescent lamp and photovoltaic cell where the following formula is used.
Stefan's cont = 2.43 X 10 (-4) { Vs’/ T}
result in joule per sqr meter per sec per quad Kelvin.
Where Vs’ = Vo +Vs in volts with Vo volts corresponding to work function of photo cathode and Vs volt corresponding to maximum kinetic energy of photo electrons which in turn correspond to photon’s of maximum energy emitted by a black body at temperature T Kelvin ( temperature of the incandescent filament which acts as a black body radiator.
Vo= minimum work function , i.e. obtain from the intercept on the Y – axis obtain from the graph of Vs( mV) and T ( in Kelvin)
Vs = voltage of the photovoltaic cell obtain from multimeter.


Homework Equations


My problem is I did not find the above formula in any book. Can anybody tell me that where can I get the derivation of the formula


The Attempt at a Solution

 
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I did not find the above formula in any book. Can anybody tell me that where can I get the derivation of the formula
 

FAQ: Experimental determination of Stefan's constant

1. What is Stefan's constant?

Stefan's constant, also known as the Stefan-Boltzmann constant, is a physical constant that relates the intensity of thermal radiation emitted by a black body to its temperature. It is denoted by the symbol σ and has a value of approximately 5.67 x 10^-8 W/m^2K^4.

2. How is Stefan's constant experimentally determined?

Stefan's constant can be experimentally determined by using a black body, which is an object that absorbs all radiation incident upon it. The intensity of thermal radiation emitted by the black body is measured at different temperatures using a sensitive instrument called a radiometer. From these measurements, the value of Stefan's constant can be calculated using the Stefan-Boltzmann law.

3. What is the significance of Stefan's constant in thermodynamics?

Stefan's constant plays a crucial role in the field of thermodynamics as it is used to calculate the total power emitted by a black body, which is a theoretical construct used to explain the emission of radiation by any object. It also helps in understanding the relationship between temperature and the amount of thermal radiation emitted by an object.

4. How accurate is the experimental determination of Stefan's constant?

The experimental determination of Stefan's constant is considered to be highly accurate, with a margin of error of less than 1%. This is due to the advancements in technology and the use of precise instruments in the experiments.

5. What are some real-world applications of Stefan's constant?

Stefan's constant has several real-world applications, such as in the field of astronomy, where it is used to calculate the luminosity of stars and other celestial bodies. It is also used in the design and efficiency calculations of thermal radiation devices, such as solar panels and thermometers. Additionally, it is used in climate science to understand the Earth's energy balance and the global warming effect.

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