This set of Testing of Materials Multiple Choice Questions & Answers (MCQs) focuses on “Brinell Hardness Test”.
1. What indenter is used for Brinell test?
a) Hardened steel ball
b) Diamond ball
c) Diamond prism
d) Steel prism
Explanation: Brinell hardness test uses hardened steel ball as an indenter. It is 10 mm diameter ball. Diamond indenter is used in the Rockwell test.
2. What test force is applied for nonferrous materials in Brinell test?
a) 50 kgf
b) 500 kgf
c) 1000 kgf
d) 3000 kgf
Explanation: Nonferrous materials are tested by lower force in Brinell test. It is about 500 kgf.
3. What test force is applied for steels and cast irons in Brinell test?
a) 500 kgf
b) 1000 kgf
c) 2000 kgf
d) 3000 kgf
Explanation: Higher level test forces are applied in steels and cast irons. It is taken 3000 kgf. While 500 kgf for nonferrous.
4. What is the most important source of error in the Brinell test?
a) Surface roughness
b) Indentation measurement
c) Coarse structure
d) Indenter error
Explanation: Brinell test is used on the rough surface. Coarse structure can also be tested using the Brinell test. Biggest source of error in indentation measurement.
5. What is the ball diameter taken for indenter of 500 kgf load in Brinell test?
a) 50 mm
b) 1 mm
c) 5 mm
d) 10 mm
Explanation: In the Brinell hardness test, ball indenter is taken. Its diameter is kept 10 mm. 1 mm diameter indenter is also used with 1 kgf test load.
6. What is the ball diameter taken for 1 kgf test load in Brinell test?
a) 1 mm
b) 5 mm
c) 10 mm
d) 50 mm
Explanation: Brinell hardness test uses ball indenter. Its diameter is kept 1 mm for lower load 1 kgf. It is taken 10 mm for 500 kgf load.
7. Brinell hardness number is not a function of ____________
a) Ball diameter
b) Impression diameter
c) Surface roughness
Explanation: Brinell hardness number is a function of ball and impression diameter and load. It is not a function of surface roughness. It is because resulting indentation averages most surface inconsistencies.
8. Brinell test method is defined in _________
Explanation: Brinell hardness test method is defined in ASTME10. It applied a predetermined test load to a carbide ball. It is of fixed diameter mostly 10 mm.
9. For Brinell hardness test _________ is kept constant.
Explanation: To obtain the same BHN with a nonstandard load or ball diameter, geometrically similar indentations must be produced. It is possible if P/D2 is maintained constant. Here P is load and D is ball diameter.
10. For very hard metals _________ ball is used in Brinell test.
a) Hardened steel
b) Alloyed steel
c) Tungsten carbide
Explanation: Hardened steel ball is used in Brinell test. But tungsten carbide ball is used in case of very hard metals. Diamond indenter is used in the Rockwell test.
11. A ball Indenter of _________ mm and _________ kgf load is used in case of gray cast iron.
a) 10, 3000
b) 5, 750
c) 10, 1000
d) 10, 500
Explanation: Gray cast iron has high hardness. So its P/D2 value is 30. Diameter is taken 10mm and 3000 kgf load.
12. Brinell test is sensitive to surface roughness.
Explanation: Brinell test can be done on the rough surface. It is possible because of a larger area of indenter averages out the hardness differential due to irregularities.
13. The load is applied for a standard time in Brinell test.
Explanation: In Brinell test load is applied for a standard time. It is generally 30 second. Unloading is carried out after this duration.
Sanfoundry Global Education & Learning Series – Mechanical Behaviour & Testing of Materials.
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