A piece of iron is heated in a flame. It first comes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is possible by using
Options
(a) Wien’s displacement law
(b) Kirchoff’s law
(c) Newton’s law of cooling
(d) Stefan’s law
Correct Answer:
Wien’s displacement law
Explanation:
Wien’s displacement law, According to this law,
λmax ∞ 1 / T or λmax x T = constant. So, as the temperature increases λ decreases.