250+ TOP MCQs on Calibration of Linear and Angular Measuring Instruments and Answers

Engineering Metrology Multiple Choice Questions & Answers on “Calibration of Linear and Angular Measuring Instruments”.

1. What is the relation between variation due to observation, manufacturing process and measuring process of a product?
a) σ_observation = σ_process + σ_measurement
b) σ_observation = σ_process – σ_measurement
c) σ_observation = σ_process * σ_measurement
d) σ_observation = σ_process / σ_measurement
Answer: a
Clarification: The variation in the observation depends upon the variation in the product due to manufacturing process and variation due to measuring process. In order to keep σobservation minimum measurement should be kept minimum so that product as a whole is reliable.

2. What is the maximum permissible error for class I micrometers?
a) 0.002 mm
b) 0.004 mm
c) 0.008 mm
d) 0.016 mm
Answer: b
Clarification: In micrometers, to cover the entire range the error in readings is checked by slip gauges. The maximum permissible error for class I micrometers is 0.004 mm and 0.008 mm for class II micrometers.

3. What is the permissible error in the perpendicular motion of ocular microscope column w.r.t. The work stage over 100 mm movements?
a) 0.04 mm
b) 0.05 mm
c) 0.07 mm
d) 0.06 mm
Answer: d
Clarification:The permissible error in the perpendicular motion of ocular microscope column w.r.t. The work stage over 100 mm movements is 0.06mm.

4. Which of the following is used to check change in ocular lines position due to column rotation in universal micrometer?
a) Dial indicator
b) Slip gauges
c) Control shaft
d) Universal microscope
Answer: c
Clarification: A special control shaft is used to check this where a right angled blade is provided at right angle to shaft diameter line. The ocular line is made to coincide with the blade and the column is titled, the shift in position of the ocular line is noted, this shift is the required error.

5. What is the least count of clinometer which is used to check reading of column rotation used for setting of helix angles in universal micrometer?
a) 1’
b) 2’
c) 3’
d) 4’
Answer: a
Clarification: The permissible error which is allowed in the entire range of column rotation is ± 5′. A clinometer is used to check this which is of 1′ least count. The clinometer is put over column top. Given Inclination is further checked with clinometer.

6. Which of the following is true for the calibration of instruments?
a) In casting and fabrication shops the measurements made are of more precise nature as compared to those made in machine shop and tool room
b) Periodical calibration is made for optical measuring instruments
c) There is no need of periodic calibration in universal microscope
d) Preventive maintenance is not necessary for optical measuring instruments
Answer: b
Clarification: In machine shop and tool room the measurements made are of more precise than those made in casting and fabrication shops, so instruments used in these shops require more frequent calibration. Annual programme can be made for periodical calibration and for general preventive maintenance in optical measuring instruments like universal microscope.

7. What is the permissible error in straight movement of longitudinal and transverse table in horizontal plane?
a) 0.002 mm
b) 0.003 mm
c) 0.004 mm
d) 0.005 mm
Answer: a
Clarification: The permissible error in straight movement of longitudinal and transverse table is 0.002 mm in horizontal plane and 0.005 mm in vertical plane. This can be checked by using a rectangular straight edge and a dial indicator of least count 0.001 mm with an attachment for fixing dial indicator.

8. Which of the following is true for checking the Relative perpendicular motion of the longitudinal and transverse carriage?
a) The permissible error allowed is 0.005 mm in 2500 mm length.
b) This is checked using a slip gauges
c) Precision square of class I or 0 is used
d) Maximum error in precision error is of ± 10″ in squareness
Answer: c
Clarification: The permissible error allowed in this case is 0.005 mm in 1100 mm length. This can be done by using a precision square of class I or class 0 accuracy having a maximum error of ± 10″ in squareness.

9. What is the maximum permissible error in wear of centres?
a) 0.04 mm
b) 0.03 mm
c) 0.02 mm
d) 0.01 mm
Answer: d
Clarification: The centres are set and checked for straightness. It can be observed while rotating the centres. The maximum error permissible for wear of centres is 0.01 mm.

10. What is the least count of dial indicators which can be calibrated using passmeter?
a) 0.01 mm
b) 0.03 mm
c) 0.05 mm
d) 0.07 mm
Answer: a
Clarification: The dial indicators of least count 0.01 mm can be calibrated by using passmeter or by micrometer dial comparator of least count 0.002 mm. The dial indicators can also be calibrated using slip gauges.