A worm gear set is designed to have pressure angle of 300 which is equal to the helix angle. The efficiency of the worm gear set at an interface friction of 0.05 is

A worm gear set is designed to have pressure angle of 300 which is equ

1.	A worm gear set is designed to have pressure angle of 300 which is equal to the helix angle. The efficiency of the worm gear set at an interface friction of 0.05 is
A.	87.9%
B.	77.9%
C.	67.9%
D.	57.9%
Answer» B.