uncettanity-mechanical eng

What is the term used to describe the probability that a mechanical part will not fail during operation?

• Stability

• Strength

• Durability

• Reliability

Which of the following is NOT a source of uncertainty in machine design?

• Temperature fluctuations

• Load distribution

• Mathematical model accuracy

• Material property variations

What does the design factor (n_d) represent in mechanical design?

• The maximum load a component can withstand

• The ratio of failure strength to allowable stress

• The efficiency of a mechanical system

• The safety margin in design

If a component has a reliability of 0.9, what does this indicate?

• It will fail 10% of the time

• It will operate perfectly

• It has a 90% chance of failure

• It is guaranteed to last forever

What is the formula for calculating reliability (R) based on failure probability (P_f)?

• R = P_f + 1

• R = 1 + P_f

• R = P_f / 1

• R = 1 - P_f

In a mechanical system, if one component fails, what type of system is it referred to?

• Composite system

• Parallel system

• Series system

• Redundant system

What is the term for the increase in stress around discontinuities in a material?

• Stress concentration

• Stress distribution

• Stress mitigation

• Stress relaxation

Which of the following factors does NOT affect the stress concentration factor (K_t)?

• Surface finish

• Geometry of the component

• Material properties

• Loading conditions

What is the maximum stress in a component with a stress concentration called?

• Design stress

• Nominal stress

• Allowable stress

• Maximum stress

If a hole in a beam has a diameter of 4 mm, what is the likely effect on stress concentration?

• Eliminates stress concentration

• Decreases stress concentration

• Increases stress concentration

• No effect on stress concentration