Question

The relation between the number of links (l) and the number of binary joints ( j) for a kinematic chain having constrained motion is given by j = 3/2 I -2 If the left hand side of this equation is greater than right hand side, then the chain is

(a) locked chain

(b) completely constrained chain

(c) successfully constrained chain

(d) incompletely constrained chain

I have been asked this question in final exam.

I need to ask this question from Simple Mechanisms in chapter Simple Mechanisms of Machine Kinematics

Answer 1

The correct option is (a) locked chain

Easiest explanation: If the left hand side is greater than the right hand side, therefore it is not a kinematic chain and hence no relative motion is possible. Such type of chain is called locked chain and forms a rigid frame or structure which is used in bridges and trusses.