Question Statement:
Which of the following statements regarding the standard specifications of tractor Power Take-Off (PTO) shafts (according to ISO 500 and ASABE standards) is/are CORRECT?
Options:
- (A) Standard Type 1 PTO operates at $540\text{ rpm}$ with a $35\text{ mm}$ ($1\frac{3}{8}\text{ inch}$) nominal diameter and $6$ straight splines
- (B) Standard Type 2 PTO operates at $1000\text{ rpm}$ with a $35\text{ mm}$ ($1\frac{3}{8}\text{ inch}$) nominal diameter and $21$ involute splines
- (C) When viewed from the rear of the tractor looking forward, the standard rotational direction of the PTO shaft is clockwise
- (D) The standard rotational direction of agricultural tractor PTO shafts is strictly counter-clockwise when viewed from the rear