12) When the two elements of a pair have a surface contact when relative motion takes place and the surface of one element slides over the surface of the other, the pair formed is known as
                    Answer is: 
                    
                                
                                
            Lower pair
Related Theory of Machines MCQ with Answers
                        Answer is: 
                        
                Party turning and partly sliding
                        Answer is: 
                        
                Force closed pair
                                Explanation: 
                                
                                                
                        
                                                    When the two elements of a pair are not connected mechanically but are kept in contact by the action of external forces, the pair is said to be a force-closed pair. The cam and follower is an example of force closed pair, as it is kept in contact by the forces exerted by spring and gravity.
