Question

Gd and T
Circle T if the statement is true. Circle F if the statement is false.
1.      The MMB and LMB symbols are only used if the datum feature has size RMB is implied if the datum feature has size and no boundary symbol is used. No material boundary symbol can be used if a feature does not have size.
2.      Unit straightness can be used if the part must be controlled per unit of measure as well as over the total length.
3.      Specific area flatness should be avoided on very large parts
4.      Circularity is a profile tolerance.
5.      Cylindricity is identified by a radius tolerance zone that establishes two perfect concentric cylinders.
6.      A parallelism tolerance zone must be smaller than the size tolerance of feature.
7.      The perpendicularity of a shaft, such as a stud or pin, to a datum feature establishes a cylindrical tolerance zone.
8.      The note EACH ELEMENT must be applied to a perpendicularity feature control frame.
9.      An angularity tolerance must have a basic angular relationship to a datum.
10. The tolerance zone descriptor of a concentricity tolerance is R.
11. Concentricity is used to establish the relationship between the axis of or more cylindrical features of an object.
12. Surface straightness can violate perfect form at MMC.
13. Geometric tolerances imply RFS unless otherwise specified.
14. A concentricity tolerance should be used if there is a need to control the axis, as in a dynamically balanced shaft. Otherwise, it is recommended that a runout or positional tolerance be used.
15. 69. A coaxial relationship can be controlled by a positional tolerance at M with the datum reference at MMB, LMB, or RMB.
16. LMC is often used to control minimum edge distance or wall thickness.
17. True position is the theoretically exact location of a feature.
18. The datum reference frame exists in theory. The theoretical reference frame is simulated by positioning the part on datum features to adequately relate the part to the datum reference frame and to restrict motion of the part relative to the reference frame.
19. When reference is made to the datum reference frame, the primary datum should be given first, followed by the secondary and tertiary datums. This is referred to as datum precedence.

Answer 1

1). True.
Least Material Boundary (LMB) and Maximum Material Boundary (MMB) are boundary condition that datum feature will not violate. LMB implies that it contains least amount of material for stated size. MMB implies it contains maximum amount of material for stated size. Regardless of material bounday (RMB) implies a condition where standard tolerence limit must be met. Thus, if size is not specified LMB, RMB and MMB cannot be written.

2). False.
Unit Surface Straighness is defined as a tolerence value which controls a line on surface. Thus, a part is controlled but not only over the length.

3). False.
Flatness is defined as how flat the surface is regardless of datum. It is the amount of waviness, for instance two big parts should mate, in such case if waviness is required for proper mating.

4). True.
Circularity is defined as how close the profile is to true circle. It is a two dimensional tolerance which controls the overall profile of circle thus ensuring that it is not too oblong or square or out of round shape.