Machine Design
The dedendum is the radial distance from the

Pitch circle to the bottom of a tooth
Pitch circle to the top of a tooth
Addendum circle to the clearance circle
Top of a tooth to the bottom of a tooth

ANSWER DOWNLOAD EXAMIANS APP

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
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
A slot is cut partly in middle of nut and then slot reduced by tightening a screw

ANSWER DOWNLOAD EXAMIANS APP