What is the mechanical advantage of the screw shown below?
A. 1.3
B. 3.9
C. 8.0
D. 10.4

Answer:
C. 8.0
Step-by-step explanation:
The mechanical advantage is got from dividing the circumference of the shaft by the pitch of the screw.
Therefore, the circumference= 2πr
=2×π×2.3mm
=14.45mm
Mechanical advantage=14.45mm/1.8mm
=8.03