Answer:
Option C,D
Explanation:
Because of non-uniform evaporation at different section, area of cross-section would be different at different sections. Region of highest evaporation rate would have rapidly reduced area and would become break up cross-section.
Resistance of the wire as whole increases with time. Overall resistance increases hence power decreases.
(p=V2R,P∝1R) as V is constant.
At break up junction temperature would be highest, thus light of highest band frequency would be emitted at those cross-section.