A cuboidal part has to be accurately positioned first, arresting six degrees of freedom and then clamped in a fixture, to be used for machining. Locating pins in the form of cylinders with hemi-spherical tips are to be placed on the fixture for positioning. Four different configurations of locating pins are proposed as shown. Which one of the options given is correct?
- Configuration $\mathrm{P}1$ arrests $6$ degrees of freedom, while Configurations $\mathrm{P}2$ and $\mathrm{P}4$ are over-constrained and Configuration $\mathrm{P}3$ is under-constrained.
- Configuration $\mathrm{P}2$ arrests $6$ degrees of freedom, while Configurations $\mathrm{P}1$ and $\mathrm{P}3$ are over-constrained and Configuration $\mathrm{P}4$ is under-constrained.
- Configuration $\mathrm{P}3$ arrests $6$ degrees of freedom, while Configurations $\mathrm{P}2$ and $\mathrm{P}4$ are over-constrained and Configuration $\mathrm{P}1$ is under-constrained.
- Configuration $\mathrm{P}4$ arrests $6$ degrees of freedom, while Configurations $\mathrm{P}1$ and $\mathrm{P}3$ are over-constrained and Configuration $\mathrm{P}2$ is under-constrained.