This set of Engineering Metrology Multiple Choice Questions & Answers (MCQs) focuses on “Gauges for Tapers”.
1. What is important in testing a tapered job?
a) Check the diameter at smaller end
b) Change of diameter per unit mass
c) Change in length per unit weight
d) Change of diameter per unit length
Explanation: Taper plug and ring gauges are used to test tapers. A taper has two ends, one of bigger diameter and other of smaller diameter. To test a tapered job it is important to check the bigger diameter and also the change of diameter per unit length.
2. How correctness of taper can be checked?
a) Draw a single line of Persian blue along the length
b) Draw two lines of Persian blue at any distance along the diameter
c) Draw three lines of Persian blue at equidistant along the length
d) No need of Persian blue, it can be checked simply by seeing the rotation of spindle
Explanation: 3 lines are drawn with Persian blue along the length on the plug gauge or spindle to test the taper. It is fitted in the gauge and rotated once or twice. If these marks of Persian blue are not rubbed evenly then the taper is not correct.
3. What is the tolerance for a bigger diameter of taper in limit gauges?
a) ± IT4
b) ± IT5
c) ± IT6
d) ± IT7
Explanation: Bigger diameter is situated in the gauge plane. Tolerance on both bigger and smaller diameter will be ± IT6 on the basic size. It can be calculated from taper ratio.
4. What is the distance (approx.) of bigger diameter from face if the value of diameter is 200mm?
a) 5 mm
b) 7 mm
c) 10 mm
d) 12 mm
Explanation: Distance of diameter at the bigger end from face depends upon the value of diameter itself. For example, if the value of diameter is 200 mm then this distance will be 2 mm or varies between 0.5 to 2 mm.
5. What is the value of hardness for plug and ring gauges used for self-holding tapers?
a) 750 to 860 HV
b) 120 to 540 HV
c) 550 to 740 HV
d) 900 to 1200 HV
Explanation: Good quality steel is used for making these gauges and these are suitably heat treated to give hardness of 750 to 860 HV and for stabilization. Gauges surfaces should be free from rust, crack and burrs.
6. Which of the following option is true for given statements regarding gauges for tapers?
Statement 1: Use of double ended gauges is very important in limit gauges for tapers.
Statement 2: Gauges should be packed in non-absorbent paper.
a) T, T
b) F, T
c) T, F
d) F, F
Explanation: Use of double ended gauges is unnecessary in this case because the diameter difference between low and high limit of the tolerances is converted into lengthwise dimension. Thus hole will be within the tolerance. Diameter at the large end of hole falls between gauge plane and other line at distance Z from it.
7. What is the tolerance for plug gauge on basic size?
a) + IT5
b) – IT7
c) + IT8
d) – IT9
Explanation: Distance between gauge plane and a free end in plug gauges is sometimes denoted as ‘a’. Distance ‘a’ varies between 2 mm to 12 mm. IT5 is the tolerance for plug gauges on the basic size.
8. Which of the following is incorrect about gauges?
a) Wear allowance is of main consideration in limit gauges for tapers
b) Cylindrical ring gauges can be used for gauging external diameters
c) Position gauges can be used to check the geometric relationship of features
d) Workshop and inspection gauges with same tolerance limits are more beneficial
Explanation: Wear allowance is not considered on the gauges. It is because of high cost is involved in manufacturing to that level of accuracy. If the tolerance limit of workshop and inspection gauges is same then the same gauges can be used for both the purposes.
Sanfoundry Global Education & Learning Series – Engineering Metrology.
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