Correct Answer - Option 3 : 2
Concept:
The following empirical relations provide the degree of freedom and the number of joints in a linkage when the number of links and the number of loops in a kinematic chain are known.
These relations are valid for linkages with turning pairs.
F = N - (2L + 1)
P1 = N + (L - 1)
where L = number of loops, N = number of links, P1 = number of single turning pairs.
Calculation:
Given:
N = 11, L = 4
F = N - (2L + 1)
F = 11 - (2 × 4 + 1) = 2
Sometimes, all the above empirical relations can give incorrect results when the links are arranged in way of double lengths or parallel links.
Parallelogram linkage with one degree of freedom is obtained. This is due to the reason that the length of the links or other dimensional properties is not considered in these empirical relations.
