Read the following statements with respect to causes of failure of heating elements and choose the CORRECT answer.
(i) Embrittlement leading to grain growth
(ii) Oxidation of element
(iii) Formation of hotspots
(iv) Contamination and corrosion
1
(i) and (ii) only
2
(i), (ii) and (iii) only
3
(i), (ii), (iii) and (iv)
4
(i) and (iv) only