In the reverted gear train, four gears of radii r1, r2, r3 and r4 are arranged as shown in the following figure. Which of the following equations represent the centre distance (D) between the shafts accurately?
1
D = r3 + r2 = r1 + r4
2
D = r1 + r4 = r3 + r2
3
D = r1 + r3 = r2 + r4
4
D = r1 + r2 = r3 + r4
5
Question Not Attempted