Q1. A wire of length L and diameter d is stretched by a force F. If the diameter is halved while keeping the length constant, what happens to the stress in the wire? (2022)
Solution:
Stress (σ) = Force (F) / Area (A). Halving the diameter increases the area by a factor of 4, thus stress quadruples.
⏱ Time: 0s
Q2. Which of the following describes the behavior of a ductile material? (2023)
Solution:
Ductile materials can be stretched into wires without breaking.
⏱ Time: 0s
Q3. Which of the following is a characteristic of elastic materials? (2023)
Solution:
Elastic materials return to their original shape after the removal of the applied force.
⏱ Time: 0s
Q4. A material has a Poisson's ratio of 0.3. If it is stretched in one direction, what is the expected lateral contraction ratio? (2019)
Solution:
Poisson's ratio (ν) = - (lateral strain) / (longitudinal strain), thus the lateral contraction ratio is 0.3.
⏱ Time: 0s
Q5. What is the bulk modulus of a material if a pressure increase of 50 MPa results in a volume decrease of 0.002 m³ for a volume of 1 m³? (2022)