43. The most suitable polymer to make one-piece hinges with the highest flexing fatigue resistance is(1 Point) 48. Heat treatment furnaces with high production capacities are(1 Point) a. Polypropylene a. Continuous furnaces b. Polystyrene b. Batch furnaces c. PVC c. Salt bath furnaces 44. The fastest cooling rate is provided by(1 Point) 49.Diffusing chromium into steel produces thin casings (0.0250.05mm ) which are(1 Point) a. Brine (salt water) a. Hard and wear resistant b. Still water b. Heat and corrosion resistant c. Still oil c. Both a and b 45. The doping process which involves diffusion of impurity element into the surface of silicon chip to produce transistors 50.Precipitation hardening consists of three steps in the order given below:(1 Point) and diodes serves to change( 1 Point) a. Solution treatment, quenching and aging. a. Electrical properties at the surface b. Quenching, solution treatment, aging b. Improve mechanical properties at the surface c. Aging, quenching, solution treatment c. Increase corrosion resistance of silicon chip. 51.For a polymer melt, the viscosity(1 Point) 46.Precipitation hardening is the principal mechanism for strengthening alloys of(1 Point) a. Decreases with shear rate a. Aluminum and magnesium b. Increases with shear rate b. Nickel-copper c. It is unaffected by shear rate c. Lead-tin 52. The most important member of the acrylics is PMMA which is known as(1 Point) 47.A polymer melt is(1 Point) a. Orlon a. Newtonian fluid b. Plexiglas b. Pseudoplastic c. Acrylic acid c. Perfectly elastic