231. Corrosion involves exchange of electrons in __________ corrosion.
Chemical
Electrochemical
Both A & B
Neither A nor B
✅ The correct answer is option C.
Materials and Construction MCQs
232. Cermets are __________ materials.
Refractory
Reinforced
Abrasive
Fully metallic
✅ The correct answer is option A.
233. The damage/deterioration of metals by the __________ action of fluids is called ‘erosion’.
Abrasive
Corrosive
Both A & B
Neither A nor B
✅ The correct answer is option A.
234. Dip stick used for measuring the level of petro fuels (e.g. petrol, diesel, fuel oil etc.) in the storage tank is usually made of
Brass
Copper
High carbon steel
Aluminium
✅ The correct answer is option A.
235. Which of the following crystal structures characterises the ferritic stainless steel?
Face centred cubic
Body centred cubic
Simple hexagonal
None of these
✅ The correct answer is option B.
236. Mixing vessel used for the chlorination of methane to produce methyl chloride is made of
Copper
Cast iron
Aluminium
High carbon steel
✅ The correct answer is option B.
237. In cold working of metal as compared to its hot working
Cracks and blow holes are eliminated
Ductility and impact strength improves
Appreciable strain hardening is produced
Yield stress, hardness and fatigue strength is not at all affected
✅ The correct answer is option C.
238. Percentage elongation of a material is a measure of its
Ductility
Brittleness
Toughness
Malleability
✅ The correct answer is option A.
239. Aqueous nitric acid is stored in
Steel drum
Stainless steel vessel
Cast iron vessel lined with acid-proof masonry brick
Cast iron vessel
✅ The correct answer is option B.
240. Addition of __________ to the steel helps in increasing the residual magnetism in steel used for making magnets.
Chromium
Nickel
Tungsten
Cobalt
✅ The correct answer is option D.