Questions and answers
Explain the working principle of your project.
Describe the energy or motion path from input to output in three or four steps, using your model or diagram.
How did you select the material?
Give the properties that mattered (strength, weight, machinability, corrosion resistance, cost) and the alternative you rejected.
What is factor of safety and what did you use?
It is the ratio of the material's strength to the allowable working stress. State your value and why, for example 2 to 3 for ductile materials under static load.
Show one design calculation.
Be ready with the calculation for your critical part: shaft diameter, bolt size, bearing life or cylinder force.
Which manufacturing processes were used?
List them in order, for example cutting, turning, drilling, welding, grinding, assembly and painting, and say which you did yourself.
What is the difference between stress and strain?
Stress is internal resisting force per unit area; strain is deformation per unit original dimension.
What type of welding did you use and why?
Name it (arc, MIG, TIG), and relate it to material thickness and availability.
What is the efficiency of your system?
Give the measured output divided by input with the readings you took.
Which software did you use for modelling and analysis?
For example SolidWorks or CATIA for the model and ANSYS for static structural analysis. Explain the load, constraints and result.
What does the von Mises stress result tell you?
It predicts yielding in ductile materials; if the maximum is below the yield strength divided by the factor of safety, the part is safe.
What are the types of gears or bearings used?
Name the type and the reason, such as spur gears for parallel shafts or deep groove ball bearings for radial load.
What is the total cost and the costliest component?
Give the figure and the top two items.
What are the limitations of your project?
State two honest limits such as capacity, manual operation or accuracy.
How can it be improved?
Suggest automation, a better material, a redesign of the weakest part or sensor integration.
What safety precautions did you take in the workshop?
Mention protective equipment and machine-specific practices you followed.
Before the viva
- Carry your calculation sheet and bill of materials
- Know every drawing dimension you are asked about
- Run the model once before the examiner arrives
- Decide who explains which sub-assembly
FAQs
Do examiners ask theory questions?
Yes. Expect basics of strength of materials, theory of machines, thermodynamics and manufacturing related to your project.
Last reviewed: 2026-10-11. Always follow the format your own department gives you.