MCQ
The unit of Stefan's constant $\sigma $ is
- A$W\,{m^{ - 2}}\,{K^{ - 1}}$
- B$W\,{m^2}\,{K^{ - 4}}$
- ✓$W\,{m^{ - 2}}\,{K^{ - 4}}$
- D$W\,{m^{ - 2}}\,{K^4}$
✓
Answer
Correct option: C.
$W\,{m^{ - 2}}\,{K^{ - 4}}$
c
(c) Stefan's law is $E = \sigma ({T^4})$
(c) Stefan's law is $E = \sigma ({T^4})$
$⇒$ $\sigma = \frac{E}{{{T^4}}}$
where,$E = $ $\frac{{{\rm{Energy}}}}{{{\rm{Area}} \times {\rm{Time}}}}$ $ = \frac{{{\rm{Watt}}}}{{{m^{\rm{2}}}}}$
$\sigma = \frac{{{\rm{Watt - }}{m^{ - 2}}}}{{{K^4}}} = Watt - {m^{ - 2}}{K^{ - 4}}$
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