46. What is the process of heating a metal to a specific temperature and then cooling it slowly to relieve internal stresses called?
a) Annealing
b) Tempering
c) Quenching
d) Forging
47. Which metal is commonly used for making water pipes and plumbing fittings due to its corrosion resistance and low toxicity?
a) Copper
b) Aluminum
c) Iron
d) PVC
48. What is the process of shaping metal by forcing it through a die orifice under high pressure called?
a) Casting
b) Forging
c) Extrusion
d) Machining
49. Which metal is primarily used for making magnets, electrical wiring, and electric motors due to its excellent conductivity and malleability?
a) Copper
b) Aluminum
c) Iron
d) Silver
50. What is the process of removing impurities from a metal by heating it in the presence of a flux called?
a) Electroplating
b) Electrorefining
c) Fluxing
d) Alloying
