A double –threaded screw has a pitch of screw 2 mm. How much

a-double-threaded-screw-has-a-pitch-of-screw-2-mm-how-much

A double –threaded screw has a pitch of screw 2 mm. How much the screw advances if it is made 3 revolutions?

A. 5

B. 6

C. 12

D. 10

This question was addressed to me by my school teacher while I was bunking the class.

The above asked question is from Construction of Screw Threads topic in section Curves used in Engineering Practice of Engineering Drawing

Right choice is C. 12

To elaborate: It is given the screw is double- threaded screw which advances to a distance of 2 times the pitch of screw for one complete turn also given pitch of 2 mm. so for one turn the screw advances to 2 x 2mm = 4 mm. The screw is made to turn 3 revolutions so the screw advances to 3 x 4 mm =12 mm.