Element of Machine Design Topic 1- 1

This type of design depends upon mathematical formulae of principle of mechanics.

• •Rational design.

• •Empirical design.

• •Industrial design.

• •Optimum design.

Answer explanation

Rational design refers to the approach of designing structures, machines, or systems based on well-established mathematical principles, such as the principles of mechanics. Engineers use mathematical formulae and theoretical analysis to develop rational designs that are well-founded and can be confidently justified. This method is in contrast to empirical design, which relies on trial and error, testing, and past experiences without a deep understanding of the underlying scientific principles. Industrial design, on the other hand, pertains more to the aesthetic and functional aspects of product design, while optimum design focuses on finding the best possible solution given specific constraints and objectives.

What type of stress is a combination of tensile and compressive stresses, leading to a change in the shape of the material without any change in its volume?

• Tensile stress

• Compressive stress

• Shear stress

• Bending stress

Answer explanation

Explanation: Bending stress occurs when a combination of tensile and compressive stresses act on an element, leading to a change in the shape of the material without any change in its volume. This type of stress is experienced in objects subjected to bending forces, like beams and bridges.

What type of stress is also known as "pulling" stress and occurs when forces act to elongate or stretch the material?

• Tensile stress

• Compressive stress

• Shear stress

• Torsional stress

Answer explanation

Explanation: Tensile stress, also known as "pulling" stress, occurs when forces act to elongate or stretch the material. It leads to an increase in the element's length. Tensile stress is commonly experienced when you stretch a rubber band.

This type of design depends upon empirical formulae based on the practice and past experience.

• •Rational design.

• •Empirical design.

• •Industrial design.

• •Optimum design.

It is the best design for the given objective function under the specified constraints. It may be achieved by minimising the undesirable effects

• Rational design

• Empirical design

• Industrial design

• Optimum design

________ is the ability of a material to resist deformation under stress

• Stiffness

• Strength

• Elasticity

• Plasticity

________ is the property of a material enabling it to be drawn into wire with the application of a tensile force.

• Ductility

• Plasticity

• Elasticity

• Brittleness

________ is property of a material which retains the deformation produced under load permanently.

• Plasticity

• Ductility

• Elasticity

• Brittleness

When a body is subjected to two equal and opposite axial pulls force, then the stress induced at any section of the body is known as __________

• tensile stress

• Shear Stress

• Simple Stress

• Compressive Stress

 $\epsilon=\frac{\ \ \ \ \ \ \ P\ \ x\ \ l}{.........\ x\ \ \delta l}$  fill in the blank