Westminster Motor Kit

This Westminster Motor kit is designed to help students to investigate and understand the principles and basic design of electric motors - by building the motors themselves, they gain a better understanding of electric motors and how they work.
The kit allows students to easily construct simple, open, working motors which can be powered using a series of batteries or, preferably, a low voltage power supply capable of delivering up to 5 Amps e.g. a Volt E-M power supply (POW-540-100). This complete kit comes with enough components to allow students to construct six individual motors.
Kit comprises:
12 x Anisotropic Ceramic Ferrite Magnets, 6 x Armatures, 6 x Mild Steel Yokes, 6 x Support Bases, 6 x Shafts, 24 x Rivets, 12 x Split Pins, 1 x Reel Insulated Copper Wire, 1 x Insulated Tubing (2.5mm Bore 30cm long), 2 x Sellotape Rolls.

Q = What are dimensions of the mild steel yokes?
A = 5 x 5 x 5 cm