Question

In a four-bar linkage, S denotes the shortest link length, L is the longest link length, P and Q are the lengths of other two links. At least one of the three moving links will rotate by ${360}^o$ if

• A. $S+L\le P+Q$
• B. $S+L>P+Q$
• C. $S+P\le L+Q$
• D. $S+P>L+Q$

Answer 1

The correct option is A $S+L\le P+Q$

According to Grashof's law for a four bar mechanism. The sum of shortest and longest link lengths should not be greater than the sum of the remaining two link lengths.

i.e. $S+L\le P+Q$