GATE Questions & Answers of Metrology and Inspection Mechanical Engineering

The height (in mm) for a 125 mm sine bar to measure a taper of $ 27^\circ\;32' $ on a flat work piece is _______ (correct to three decimal places).

Cylindrical pins of diameter $\style{font-family:'Times New Roman'}{15^{\pm0.020}\mathrm{mm}}$ are being produced on a machine. Statistical quality control tests show a mean of 14.995 mm and standard deviation of 0.004 mm. The process capability index $ C_P $ is

Assume that the surface roughness profile is tringular as shown schematically in the figure. If the peak to valley height is 20 μm, the central line average surface roughness $ R_\alpha $ (in μm) is


The standard deviation of linear dimensions P and Q are 3 µm and 4 µm, respectively. When assembled, the standard deviation (in µm) of the resulting linear dimension (P+Q) is_________

A cylindrical pin of 25+0.020+0.010 mm diameter is electroplated. Plating thickness is 2.0±0.005 mm. Neglecting the guage tolerance, the diameter (in mm, up to 3 decimal points accuracy) of the GO ring guage to inspect the plated pin is___________

The “Jominy test” is used to find

Match the following:

P. Feeler gague I. Radius of an object
Q. Fillet gauge II. Diameter within limits by comparison
R. Snap gauge III. Clearance or gap between components
S. Cylindrical plug gauge IV. Inside diameter of straight hole


For the situation shown in the figure below the expression for $ H $ in terms of $ r,R $ and $ D $ is


Holes of diameter 25.0+0.020+0.040 mm are assembled interchangeably with the pins of diameter 25.0-0.008+0.005 mm . The minimum clearance in the assembly will be

In the assembly shown below, the part dimensions are:



Assuming the normal distributions of part dimensions, the dimension L4 in mm for assembly condition would be:

Which one of the following statements is TRUE?

Which one of the following instruments is widely used to check and calibrate geometric features of machine tools during their assembly?

For the given assembly: 25 H7/g8, match Group A with Group B

Group A   Group B
P. H       I. Shaft Type
Q. IT8   II. Hole Type
R. IT7   III. Hole Tolerance Grade
S. g   IV. Shaft Tolerance Grade

The diameter of a recessed ring was measured by using two spherical balls of diameter d2=60 mm and d1=40 mm as shown in the figure.

The distance H2=35.55 mm and H1=20.55 mm. The diameter (D, in mm) of the ring gauge is _______

A GO-No GO plug gauge is to be designed for measuring a hole of nominal diameter 25 mm with a hole tolerance of ± 0.015 mm. Considering 10% of work tolerance to be the gauge tolerance and no wear condition, the dimension (in mm) of the GO plug gauge as per the unilateral tolerance system is

A metric thread of pitch 2 mm and thread angle 60° is inspected for its pitch diameter using 3-wire method. The diameter of the best size wire in mm is

Cylindrical pins of 25+0.010+0.020 mm diameter are electroplated in a shop. Thickness of the plating is 30±2.0 micron. Neglecting gage tolerances, the size of the GO gage in mm to inspect the plated components is

In an interchangeable assembly, shafts of size 25.000+0.040-0.010mm mate with holes of size 25.000+0.030+0.020mm. The maximum interference (in microns) in the assembly is

A hole is dimension $\phi\mathit9^{\begin{array}{c}+0.015\\+0\;\;\;\;\;\;\;\end{array}}$ mm. The corresponding shaft is of dimension $\phi\mathit9^{\begin{array}{c}+0.010\\+0.001\end{array}}$ mm. The resulting assembly has

A shaft has a dimension,?35-0.009-0.025. The respective values of fundamental deviation and tolerance are

A taper hole is inspected using a CMM, with a probe of 2mm diameter. At a height, Z=10mm from the bottom, 5 points are touched and a diameter of circle (not compensated for probe size) is obtained as 20mm. similarly, a 40mm diameter is obtained at a height Z = 40mm. the smaller diameter (in mm) of hole at Z = 0 is

What are the upper and lower limits of the shaft represented by 60 f8?

Use the following data:

Diameter 60 lies in the diameter step of 50-80 mm
Fundamental tolerance unit, i, in µm = 0.45 D1/3 + 0.001 D, where D is the representative size in mm;
Tolerance value for IT8=25i. Fundamental deviation for ‘f’ shaft = -5.5D0.41

A displacement sensor (a dial indicator) measures the lateral displacement of a mandrel mounted on the taper hole inside a drill spindle. The mandrel axis is an extension of the drill spindle taper hole axis and the protruding portion of the mandrel surface is perfectly cylindrical. Measurements are taken with the sensor placed at two positions P and Q as shown in figure. The readings are recorded as Rx = maximum deflection minus minimum deflection, corresponding to sensor position at X, over one rotation.

If Rp=RQ>0 , which one of the following would be consistent with the observation?

A hole is specified as 400.0500.000 mm. The mating shaft has a clearance fit with minimum clearance of 0.01 mm. The tolerance on the shaft os 0.04 mm. The maximum clearance in mm between the hole and the shaft is