Q. The passive state of a metal is often relatively unstable and subject to damage.

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Q. Which of the following is/are the metal/alloys that demonstrate active-passive transitions?

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Q. Which of the following is/are correct regarding the active region of metals?

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Q. The Trans passive region is the region in which the corrosion rate increases with an increase in potential.

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Q. Which of the following is/are the important characteristics of active-passive transitions of a metal?

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Q. Which of the following metal doesn’t possess a trans passive region?

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Q. Which of the following metals/alloys passivates spontaneously in acid solutions containing oxidizers or dissolved oxygen?

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Q. Which of the following is/are the applications of mixed-potential theory?

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Q. Which of the following is/are correct when oxidizing agents are added to a corrosion system containing a non-passivating metal?

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Q. The corrosion rate is usually dependent at low velocity whereas at high velocities it becomes independent.

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Q. Which of the following type of polarization has a negligible effect on velocity?

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Q. Severe corrosion of metals occurred when coupled with platinum is due to the higher current density for hydrogen evolution but not due to the reversible potential of the platinum-platinum ion electrode.

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Q. The reversible potential of gold is more positive than platinum in emf series whereas in galvanic series the position of gold is below platinum.

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Q. In a galvanic couple, the corrosion rate of the metal with active corrosion potential is accelerated whereas the corrosion rate of noble metal retards preferentially.

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Q. Which of the following metals that are spontaneously passivated on coupling with platinum?

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Q. Which of the following is/are correct regarding the potentiostat method?

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Q. What is meant by anodic protection?

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Q. The optimum potential for anodic protection is in the mid of passive region since it permits slight variations.

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Q. Which of the following noble metals will improve the corrosion resistance of titanium and chromium on galvanic coupling?

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Q. Stainless steels containing small quantities of platinum passivates more readily in the presence of oxygen, ferric salts, and other oxidizing agents.

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