Final answer:
Technician A and B are both correct; universal joints indeed speed up and slow down during their operational cycle, and this speed variation is dependent on the angle of the joint, with greater angles leading to more significant speed variations.
Step-by-step explanation:
The question pertains to universal joints and their operational characteristics, specifically in regards to speed variation as they rotate. Technician A is correct in saying that universal joints do speed up and slow down during their operational cycle. This phenomenon is known as fluctuation of angular velocity and is caused by the constant change in the angle of the driving and driven shafts as they rotate.
Technician B is also correct in stating that the speed variation depends on the angle of the universal joint. The greater the angle between the input and output shafts, the more significant the speed variation will be. This is due to the geometrical constraints of the universal joint, which results in a non-uniform motion of the output shaft when the input shaft rotates at a constant speed.
Therefore, the correct answer is C. Both Technician A and B are correct.