Under what condition is a kinematic chain considered unconstrained_____________?
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Answer: C. L.H.S. < R.H.S
Explanation
When mobility calculations yield an excess of degrees of freedom, the chain is deemed unconstrained. The mathematical condition where LHS is less than RHS indicates multiple uncoordinated relative motions. Such chains cannot transmit motion predictably without adding extra constraints or links. Kinematic chain mobility is evaluated using Grübler's or Kutzbach's criteria equations. A properly constrained mechanism has a degree of freedom equal to one for single-input devices. An unconstrained chain exhibits loose or erratic movement due to insufficient geometric constraints.
Engineers must check mobility criteria during the preliminary design phase of complex machinery. Building an unconstrained linkage results in a floppy structure incapable of performing useful work. Adding appropriate links or fixing specific joints corrects unconstrained kinematic chains effectively. Option A represents a properly constrained mechanism with zero or standard mobility degrees. Option B indicates a locked structure with negative or zero effective mobility. Option D is false because well-established mathematical criteria exist for checking chain mobility.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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