[Physics Class Notes] on Stefan Boltzmann Constant Pdf for Exam

Josef Stefan and Ludwig Boltzmann together proposed the law of black body radiation. According to the law, the total heat radiation emitting from a black body is directly proportional to the fourth power of the thermodynamic or absolute temperature of the black body. The proportionality constant used for this equation was named Stefan Boltzmann constant and was expressed by the Greek symbol σ. 

Value of Stefan Boltzmann Constant

Stefan’s constant was universally accepted, and its value was derived as 

σ = 5.670367(13) × 10-8 W ⋅ m-2. K-4

From the above, the SI unit of Stefan’s constant can be written as W ⋅ m-2. K-4. 

Here, 

• W stands for Watt. 

• m for Metre. 

• K for Kelvin. 

Dimensional formula for Stefan Boltzmann law constant will be [[M^1T^{-3}K^{-4}]].

Beside the SI unit,  Stefan Boltzmann Constant can be expressed in various other systems of the unit as well. Here, look at the table below for the same. 

Formula for Stefan Boltzmann Constant Value

This value is derived using various other constants or evaluated experimentally as shown below:

σ = 2 . π5 KB4 / 15 h3 c2 = 5.670367(13) × 10-8 J . m-2. S-1 . K-4

Refer to the table mentioned below to know the physical quantities used in this equation. 

According to CODATA, this Value of Stefan constant can be evaluated utilising this gas constant as mentioned below. 

σ = 2π5 R4 / 15 h3 c2 NA4 = (32 π5 h R4 R∞4) / (15 Ar(e)4 Mu4 c6 α8) 

Refer to the table mentioned below to know the physical quantities used in this equation and their values. 

You need to give special attention to these tables as these are something that have more to do understanding before learning. You need to keep in mind that this part cannot be mugged up in any way. Therefore, your focus should be on gaining clarity of basic concepts. For this, tutors hold your hand from initial to the end where you can attain clarity on simple to complex topics. Once you have gained knowledge on concepts, then you can move ahead towards uses and applications. 

Stefan Boltzmann constant – Uses and Applications

There are several scenarios in Physics when this constant is used for determining various physical quantities and other constants. Here is a list of few applications – 

These are a few applications of Stefan constant value amongst several others. Knowing the value of this constant and how it is derived will help you in the calculation of several other physical quantities. Going further, answer the questions mentioned below and test your understanding of this topic. 

Multiple Choice Questions 

1.Choose the appropriate option which holds true for Stefan Boltzmann thermal radiation law. 

1. q = α A T5

2. q = α A T

3. q = α A T3

4. q = α A T4

Ans: d 

2.Choose the appropriate unit for Stefan Boltzmann’s constant. 

1. Kcal/hr K4

2. Kcal/m2 hr K4

3. Kcal/m2 K4

4. Kcal/m hr K4

Ans: b 

You will be able to extend your learning about the Stefan’s constant and more with ’s study materials. Now you can also download our app and easily learn the complex topics with the study notes prepared by our expert tutors. 

1.What is the unit of Stefan’s constant?

Ans: The SI Unit of Stefan’s constant can be written as W ⋅ m-2. K-4. In CGS units, it can be expressed as erg.cm2.s1.K4, and in US customary units, it is BTU.hr1.ft2.°R4.

To support the preparation of students, has also included a few MCQs that give an idea of the types of multiple types questions that could be there in the final examination. For regular practice, join classes using the web portal or mobile applications.