## Thursday, August 20, 2009

### Mechanical Engineering Board Exam Questions Part 2

Mechanical Board Exam Questions from Machinery's Handbook.
Topic: Machine Design : Strength of Materials

1.______ is the amount by which a dimension of a body changes when the body is subjected to a load, divided by the original value of the dimension
a. stress
b. unit strain
c. modulus of resilience
d. modulus of elasticity

2.______is the maximum stress to which a test specimen may be subjected and still
a. elastic limit
b. rupture point
c. yield point
d. elastic limit

3. _______ is the ratio of unit stress to unit strain within the proportional limit of a material in tension or compression.
a. Modulus of Elasticity
b. Modulus of Resilience
c. Strain
d. unit strain

4._______is the ratio of lateral strain to longitudinal strain for a given material
subjected to uniform longitudinal stresses within the proportional limit.
a. Poisson's ratio
b. unit stress
c. strain
d. Young's modulus of elasticity

5._______is the maximum stress that can be applied without permanent deformation of the test specimen.
a.Yield Strength
b. Yield Point
c. Utimate Strength
d. Rupture strength

6. _______ is the ratio of unit stress to unit strain within the proportional limit of a material in shear.
a. Modulus of Elasticity
b. Modulus of Resilience
c. Modulus of Rigidity
d. Young's Modulus

7. When strain cycling is produced by a fluctuating temperature field, the failure process is termed _____.
a. Thermal Fatigue
b. Corrosion Fatigue
c. Surface or Contact Fatigue
d. Creep

8. ______ is the ratio of length l of the column in inches divided by the least radius of gyration r of the cross-section.
a. Poisson's ratio
b. slenderness ratio
c. strain
d. Modulus of elasticity

9.Rankine formula for colunms is also known as...
a. Straight line formula
b. Gordon's Formula
c. secant formula
d. Euler's Formula

10. This is the most widely used of all spring materials for small springs operating at temperatures up to about 250F.
a.Music Wire

11.This general-purpose spring steel is commonly used for many types of coil springs where the cost of music wire is prohibitive and in sizes larger than are available in music wire.
a.Music Wire

12.This grade is used for general-purpose springs where cost is the most important factor.
a.Music Wire

13. This alloy, the first constant-modulus alloy used for
hairsprings in watches, is an austenitic alloy hardened only by cold-drawing and cold-rolling.
a.Elinvar
b.Elgiloy
c.Dynavar
d.Ni-Span C

14.This spring service is for 1,000 to 10,000 deflections.
a.Severe Service
b.Light Service
c.Average Service
d.Extra Light Service

15.______ is the highest stress, or range of stress, in pounds per square inch that can be repeated indefinitely without failure of the spring.
a. Endurance Strength
b. Endurance limit
c. Elastic Limit
d. Proportional Limit