Surface Roughness Measurement - Mechanical Engineering (MCQ) questions and answers

1)   Calculate CLA value of roughness for a graph, having 100 horizontal magnification and 10000 vertical magnification for a sampling length of 1.2 mm. The areas above the datum line are 100 mm2, 120 mm2, 140 mm2, 40 mm2 and below the datum line are 80 mm2, 40 mm2, 150 mm2, 90 mm2.

a. 0.6333 micron
b. 6.333 micron
c. 0.912 micron
d. 0.079 micron
Answer  Explanation 

ANSWER: 0.6333 micron

Explanation:
No explanation is available for this question!


2)   Match the following Group 1 items with Group 2 items

1. Flaw ---------------------------------------------- A. Secondary texture
2. Actual surface ---------------------------------- B. Surface which does not exist  
3. Nominal surface ------------------------------- C. Primary texture
4. Waviness ---------------------------------------- D. Designer prescribes the surface
5. Roughness --------------------------------------- E. Irregularities occurring at one place


a. 1 - A, 2 - B, 3 - D, 4 - C, 5 - E
b. 1 - D, 2 - E, 3 - D, 4 - C, 5 - C
c. 1 - E, 2 - D, 3 - B, 4 - A, 5 - C
d. 1 - C, 2 - A, 3 - D, 4 - B, 5 - E
Answer  Explanation 

ANSWER: 1 - E, 2 - D, 3 - B, 4 - A, 5 - C

Explanation:
No explanation is available for this question!


3)   What does effective profile mean, while defining a surface texture?

a. Workpiece having repetitive irregularities
b. Roughness can be measured in this imaginary profile
c. Real contour of a surface
d. All of the above
Answer  Explanation 

ANSWER: Real contour of a surface

Explanation:
No explanation is available for this question!


4)   Which among the following causes first order surface irregularity?

a. Lack of straightness
b. Lack of rigidity
c. Feed and speed
d. Vibrations
Answer  Explanation 

ANSWER: Lack of straightness

Explanation:
No explanation is available for this question!


5)   Which among the following is a type of direct measuring instrument of roughness?

a. Micro interferometer
b. Wallace surface dynamometer
c. Profilometer
d. None of the above
Answer  Explanation 

ANSWER: Profilometer

Explanation:
No explanation is available for this question!


6)   Which principle does Taylor-Hobson-Talysurf tester work on?

a. Capacitive demodulating principle
b. Intensity modulating principle
c. Inductive modulating principle
d. Carrier modulating principle
Answer  Explanation 

ANSWER: Carrier modulating principle

Explanation:
No explanation is available for this question!


7)   Which of the following methods is unreliable to evaluate the surface finish?

a. Electrical stylus profilometer
b. Wallace surface dynamometer
c. Profilograph
d. Tomlinson surface tester
Answer  Explanation 

ANSWER: Wallace surface dynamometer

Explanation:
No explanation is available for this question!


8)   Which of the following statements is true?

a. Photocell is used to measure light intensity
b. Planimeter is used to measure surface roughness
c. According to Indian Standard 696 roughness valve is to be measured in millimeter
d. All statements are true
Answer  Explanation 

ANSWER: Photocell is used to measure light intensity

Explanation:
No explanation is available for this question!


9)   What is ten point height method?

a. It is the average sum of ten highest points measured within sampling length
b. It is the average difference of five highest points and five deepest valleys measured within sampling length
c. It is the sum of ten highest points divided by sum of ten deepest valleys measured within sampling length
d. It is the average sum of five highest points and five deepest valleys measured within sampling length
Answer  Explanation 

ANSWER: It is the average difference of five highest points and five deepest valleys measured within sampling length

Explanation:
No explanation is available for this question!


10)   Which method is calculated considering geometric average of ordinates?

a. Centre line average method
b. Peak to valley height method
c. Root mean square method
d. All of the above
Answer  Explanation 

ANSWER: Root mean square method

Explanation:
No explanation is available for this question!