This set of Testing of Materials Multiple Choice Questions & Answers (MCQs) focuses on “Indentation Hardness”.
1. Indentation hardness gives a rough idea of ____________
a) Yield strength
c) Tensile strength
d) Compressive strength
Explanation: Indentation hardness gives a rough idea of tensile strength. It is linearly related to tensile strength. This relation is different for different materials.
2. Which one is a micro-indentation test?
Explanation: Brinell, Rockwell and shore hardness tests are macro-hardness tests. Knoop hardness test is micro-hardness test. This classification is based on test load.
3. __________ is used for measuring the hardness of brittle materials.
a) Brinell hardness test
b) Rockwell hardness test
c) Shore hardness test
d) Vickers hardness test
Explanation: Vickers hardness test Is used for measuring the hardness of brittle materials. It produces shallow indentation. So not much plastic deformation is produced.
4. For hardness test, where test load is larger than 1 kgf, is categorized as __________
a) Micro-hardness test
b) Macro-hardness test
c) Scratch hardness test
d) Reboud hardness test
Explanation: Macro-indentation is applied to materials with test load more than 1 kgf. Micro-indentation tests on the other hand are applied with test load lesser than 1 kgf. Scratch and rebound tests are different than indentation tests.
5. Which one of the following is not an indentation hardness test?
Explanation: Shore hardness test is categorized as rebound test. Rockwell, Vickers and Brinell hardness tests are indentation hardness tests. These are destructive tests.
6. __________ measures the resistance of a sample to material deformation due to a constant compression load from a sharp object.
a) Scratch hardness
b) Rebound hardness
c) Indentation hardness
d) Leeb test
Explanation: Indentation hardness measures the resistance of a sample to material deformation due to a constant compression load from a sharp object. These are primarily used in engineering and metallurgy.
7. For higher __________ indentation hardness is also higher.
Explanation: For a material having high stiffness, hardness will be higher. Stiffness is resistance against bending. Ductility if is higher of a material, hardness will be low.
8. Indentation hardness is measured by _____________
a) Size of indentation
c) Height of rebound
d) Area under stress-strain curve
Explanation: An indenter is used in indentation test. The size of indentation is used to measure hardness. It shows the resistance against permanent deformation.
9. Hardness steel ball is used in __________ test.
Explanation: Brinell hardness test uses hardened steel ball as an indenter. It is 10 mm diameter ball. Subjected load is 3000 kg.
10. Vickers hardness test gives accurate readings.
Explanation: Vickers hardness test gives a most accurate reading. Only one type of indenter is used for all materials.
11. Leeb is an indentation hardness test.
Explanation: Leeb is a rebound hardness test. It was developed in 1975. It provides a portable hardness test for metals.
Sanfoundry Global Education & Learning Series – Mechanical Behaviour & Testing of Materials.
To practice all areas of Mechanical Behaviour & Testing of Materials, here is complete set of 1000+ Multiple Choice Questions and Answers.