Machine Design
Jam nut is a locking device in which

One smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
A slot is cut partly in middle of nut and then slot reduced by tightening a screw
Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter spitted and bent in reverse direction at other end
A hard fibre or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip

ANSWER DOWNLOAD EXAMIANS APP

Machine Design
Turn buckle has

No threads
Left hand threads on both ends
Right hand threads on bout ends
Left hand threads on one end and right hand threads on other end

ANSWER DOWNLOAD EXAMIANS APP

Machine Design
For unequal width of butt straps, the thicknesses of butt straps are

0.75 t for wide strap on the inside and 0.625 t for narrow strap on the outside
0.75 t for both the straps on the inside and outside
0.75 t for narrow strap on the inside and 0.625 t for wide strap on the outside
0.625 t for both the straps on the inside and outside

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON Machine Design