Technician A says that the pitch line diameter of a spur gear exceeds its root diameter.Technician B says that when a pair of gears are properly in mesh,there should be contact between the apex (outside diameter) of each gear tooth with its opposite's root.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Pitch Line Diameter

Pitch line diameter refers to the diameter of the pitch circle in a gear, where the teeth of two gears in mesh are considered to roll without slipping, crucial for gear design and meshing.

Root Diameter

The diameter of a gear or screw at the base of the teeth or threads, critical for calculating gear strength and meshing characteristics.