MCQs in Engineering Materials Part IV

(Last Updated On: December 21, 2017)

This is the Multiples Choice Questions Part 4 of the Series in Engineering Materials as one of the General Engineering and Applied Sciences (GEAS) topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including past Board Questions in General Engineering and Applied Sciences (GEAS) field.

Online Questions and Answers in Engineering Materials Series

Following is the list of multiple choice questions in this brand new series:

Continue Practice Exam Test Questions Part IV of the Series

Choose the letter of the best answer in each questions.

151. Yellow brass contains approximately how many percent of zinc?

• A. 20 %
• B. 50 %
• C. 30 %
• D. 40 %

152. Indicate the false statement.

• A. Aluminum bronzes contain no tin.
• B. Silicon bronzes are usually used for marine application and high-strength fasteners.
• C. Bronze is a copper-tin alloy.
• D. Tin is relatively soluble in copper.

153. What is the most abundant metal in nature?

• A. Aluminum
• B. Steel
• C. Iron
• D. Copper

154. Indicate the false statement about aluminum.

• A. It has 1/3 the weight of steel.
• B. It has 1/3 of the stiffness of steel.
• C. It has high strength-to-weight ratio.
• D. It has poor thermal and electrical conductivity.

155. What is the effect to aluminum with iron as the alloying element?

• A. Reduce hot-cracking tendencies in casting.
• B. Improve conductivity
• C. Lowers castability
• D. Improves machinability

156. What is the effect to aluminum with copper as alloying element?

• A. Increase strength up to about 12%
• B. Reduces shrinkage
• C. Improves machinability
• D. Increases fluidity in casting

157. Which of the following are two well-known nickel alloys with magnetic properties ideal for permanent magnets?

• A. Invar and Nilvar
• B. Nichrome and Constantan
• C. Elinvar and Invar
• D. Alnico and Conife

158. The Portland cement is manufacture from the following elements except:

• A. lime
• B. silica
• C. alumina
• D. asphalt

159. What gives the average ratio of stress to strain for materials operating in the nonlinear region in the stress-strain diagram?

• A. Modulus of elasticity
• B. Proportionality limit
• C. Secant modulus
• D. Tangent modulus

160. What test determines the hardenability of a steel specimen?

• A. Jominy end-quench test
• B. The lever rule
• C. Gibb’s phase test
• D. Stress relief test

161. What steel relief process is used with hypocutectoid steels to change martenite into pearlite?

• A. Tempering
• B. Normalizing
• C. Annealing
• D. Spheroidizing

162. What is another term for tempering?

• A. Recrystalization
• B. Annealing
• C. Spheroidizing
• D. Drawing or toughening

163. All are steel surface hardening processes except one. Which one?

• A. Carburizing
• B. Flame hardening
• C. Nitriding
• D. Annealing

164. For metric wire gage, the No. 2 wire is ________ in diameter.

• A. 0.1 mm
• B. 0.2 mm
• C. 0.3 mm
• D. 0.4 mm

165. Bus bars of rectangular cross section are generally used for carrying ________.

• A. high electric current
• B. low electric current
• C. high voltage
• D. low voltage

166. What are used for interconnection on printed-circuit boards?

• A. Unlaminated flat conductors
• B. Insulated conductors
• C. Rounded flexible conductors
• D. Flat flexible conductors

167. Yellow brass is a copper alloy with improved mechanical properties but reduced corrosion resistance and electrical conductivity. How many percent of yellow brass is copper?

• A. 65 %
• B. 35 %
• C. 55 %
• D. 45 %

168. What type of copper alloy is used as collectors for electric generator?

• A. yellow brass
• B. Beryllium copper
• C. Tin Bronze
• D. Phosphor bronze

169. What is the electrical resistivity of pure copper in μΩ-cm?

• A. 1.76
• B. 1.71
• C. 1.67
• D. 3.10

170. What should be the resistivity in μΩ-cm of a resistor material?

• A. 200 – 300
• B. 100 – 200
• C. 50 – 150
• D. 10 – 50

171. What is the most widely used dielectric material in the electrical and electronics industry?

• A. Polymer
• B. Plastic
• C. Rubber
• D. All of the above

172. What are natural or synthetic rubber like materials which have outstanding elastic characteristics?

• A. Thermosetting plastics
• B. Polymers
• C. Elastomers
• D. Thermoplastic plastics

173. What are cellular forms of urethanes, polystyrenes, vinyls, polyehtylenes, polypropylenes, phenolics, epoxies and variety of other plastics?

• A. Thermoplastic plastics
• B. Plastic foams
• C. Polymers
• D. Thermosetting plastics

174. What is the widely used electrical insulator?

• A. Plastic
• B. Polymer
• C. Epoxy
• D. Paper

175. What is the dielectric strength of an unimpregnated cellulose paper or kraft paper?

• A. 6 to 12 MV/m
• B. 8 to 14 MV/m
• C. 10 to 16 MV/m
• D. 12 to 18 MV/m

176. What is the most widely known carbide?

• A. Carbon carbide
• B. Lead carbide
• C. Germanium carbide
• D. silicon carbide

177. Class I capacitors have dielectric constants are up to _____.

• A. 100
• B. 200
• C. 300
• D. 500

178. What are the typical dielectric constants of class II capacitors?

• A. 500 to 10,000
• B. 1,000 to 10,000
• C. 500 to 5,000
• D. 100 to 1,000

179. What are the most widely used general-purpose coatings?

• A. Alkyds
• B. Acrylics
• C. Epoxies
• D. Vinyls

180. What is widely used in the electronic industry as a structural member, such as tube envelopes, hermetic seals to metals or ceramics, protective coating on hybrid and integrated circuits, etc.?

• A. Glass
• B. Plastic
• C. Silica
• D. Film

181. What refers to glasses which are devitrified about 100oC below their softening point to form a very fine network of crystalline phase?

• A. Fused silica
• B. Glass ceramics
• C. Fused quartz
• D. Fiber glass

182. The percentage change in magnetic properties of materials resulting from temperature aging called the ____________.

• A. aging index
• B. aging factor
• C. aging coefficient
• D. aging point

183. The change in electrical resistance due to the application of magnetic field is called ____________.

• A. magnetic anisotropy
• B. magnetoresistance
• C. magnetostriction
• D. magnetizing factor

184. Which material is used for de application such as electromagnetic cores and relays?

• A. Iron
• B. Copper
• C. Steel
• D. Aluminum

185. Which of the following is known as “electrical steel”?

• A. Silicon steel
• B. Stainless steel
• C. Carbon steel
• D. Cast Steel

186. What is the highest-frequency ferrite?

• A. Garnet
• B. Spinel
• C. Mumetal
• D. Superinvar

187. Which material is used for Schottky barrier diodes, light-emitting diodes, Gunn diodes and injection lasers?

• A. Gallium Arsenide
• B. Silicon Carbide
• C. Selenium
• D. Gallian Phosphide

188. What material is used for electroluminescent diodes which can emit either green or red light?

• A. Gallium Arsenide
• B. Silicon Carbide
• C. Selenium
• D. Gallium Phosphide

189. Lead compounds such as load sulfide, selenide and telluride may be used for which application?

• A. Diodes and transistors at low temperature
• B. Infrared detectors
• C. Thermoelectric applications
• D. All of the above

190. For hardness penetration test, the Rockwell test uses what type of penetrator?

• A. Sphere
• B. Square pyramid
• C. Asymmetrical pyramid
• D. Cube

191. What is the combination of cutting and scratch test of a material?

• A. Knoop test
• B. Vickers test
• C. File hardness test
• D. Toughness test

192. What refers to the strain energy per unit volume required to reach the yield point?

• A. Elastic toughness
• B. Fatigue
• C. Hardness
• D. Creep strain

193. The following are typical properties of ceramics except one. Which one?

• A. High melting point
• B. High compressive strength
• C. High corrosion resistance
• D. High thermal conductivity

194. What refers to the average number of mers in the molecule, typically several hundred to several thousand?

• A. Polymerization constant
• B. Polymerization factor
• C. Degree of polymerization
• D. Polemerization index

195. What nickel alloy has high electrical and corrosion resistance and high strength at red heat temperature and contain 15 to 20% chromium?

• A. Alnico
• B. Nichrome
• C. Invar
• D. Nilvar

196. Silicon bronze contains how many percent of silicon?

• A. 96 %
• B. 3 %
• C. 1 %
• D. 69 %

197. What element is added to copper to increase its strength and fatigue properties?

• A. Silicon
• B. Aluminum
• C. Beryllium
• D. Zinc

198. What element is added to copper to make it extremely hard?

• A. Aluminum
• B. Zinc
• C. Lead
• D. Silicon

199. What element constitutes the major component of most bronzes?

• A. Zinc
• B. Tin
• C. Lead
• D. Aluminum

200. What is the most common alloying ingredient in copper?

• A. Tin
• B. Lead
• C. Zinc
• D. Aluminum

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