Physics And Measurement Question 316
Question: The unit of Stefan’s constant $ \sigma $ is
[ MP PMT 1992; CBSE PMT 2002]
Options:
A) $ W{{m}^{-2}}{{K}^{-1}} $ .
B) $ Wm^{2}{{K}^{-4}} $
C) $ W{{m}^{-2}}{{K}^{-4}} $
D) $ W{{m}^{-2}}K^{4} $
Show Answer
Answer:
Correct Answer: C
Solution:
Stefan’s law is $ E=\sigma (T^{4}) $
therefore $ \sigma =\frac{E}{T^{4}} $ where, $ E= $ $ \frac{Energy}{Area\times Time} $ $ =\frac{Watt}{{{m}^{2}}} $
$ \sigma =\frac{\text{Watt-}{{m}^{-2}}}{K^{4}}=Watt-{{m}^{-2}}{{K}^{-4}} $
