Q 30. A compound gear train with gears P,Q,R and S has number of teeth 20, 40, 15
and 20, respectively. Gears Q and R are mounted on the same shaft as shown in
the figure below. The diameter of the gear Q is twice that of the gear R. If the
module of the gear R is 2mm, the center distance in mm between gears P and
S is.
(A) 40
(B) 80
(C) 120
(D) 160
Answer: (B )
Explanation:
