DESIGN OF MACHINE ELEMENT- UNIT 1 MOODLE-15 MARCH 2025

Which of the following is the first step in the machine design process?

• Selection of materials

• Conceptual design

• Final design

• Analysis of stresses

Which factor is NOT commonly considered when selecting materials for machine design?

• Mechanical properties

• Cost of material

• Density

• Electrical properties

What is the primary purpose of a factor of safety in machine design?

• To minimize cost

• To prevent failure by ensuring a margin of safety

• To reduce material weight

• To increase the strength of materials

Which type of stress is associated with forces that cause a material to stretch or compress along its length?

• Bending stress

• Torsional stress

• Direct stress

• Shear stress

The selection of material for a machine design primarily depends on which of the following mechanical properties?

• Electrical conductivity

• Hardness

• Density

• Young’s Modulus

What is the purpose of fits and tolerances in machine design?

• To increase manufacturing cost

• To ensure proper assembly and functionality

• To reduce material costs

• To allow for greater flexibility in design

Which of the following tolerances would likely be used for high-precision parts in machine design?

• Loose fit

• Medium fit

• Close fit

• Clearance fit

In a press fit, the tolerance is designed so that:

• The hole is slightly larger than the shaft

• The hole and shaft are exactly the same size

• The shaft is slightly larger than the hole

• Both the hole and shaft are oversized

Which stress equation is used to calculate direct stress?

• σ = F/A

• σ = M/I

• τ = T/J

• σ = E · ΔL/L

The bending stress equation σ = M/S is used to calculate which type of stress?

• Torsional stress

• Shear stress

• Bending stress

• Direct stress