state gov TSPSC Polytechnic Lecturer Mock Test 2022 Design of Machine Elements Power Screws Efficiency of Screws
Which of the following equation is valid for the maximum efficiency of square threaded screw? [where α = Helix angle, ϕ = Friction angle]
1
α = (90 - ϕ) degree
2
ϕ = (90 + α) degree
3
\(\alpha = \left(45 - \frac{\phi}{2}\right)\rm degree\)
4
\(\phi= \left(45 - \frac{\alpha}{2}\right)\rm degree\)