Final answer:
Tech A is incorrect; fixed calipers have pistons on both sides of the rotor, whereas Tech B is correct that sliding calipers use pistons on only one side.
Step-by-step explanation:
The correctness of the statements made by Tech A and Tech B is contingent on the type of caliper design. Tech A is incorrect when stating that fixed calipers use one or more pistons only on one side of the rotor. In fact, fixed calipers typically employ pistons on both sides of the brake rotor to apply braking force evenly. On the other hand, Tech B correctly notes that sliding calipers, which can also be referred to as floating calipers, use one or more pistons located on only one side of the rotor. The caliper slides on guides or rails to apply pressure to the other side of the rotor.
Hydraulic brakes operate by Pascal's principle, which suggests that when pressure is applied to a confined fluid, the pressure change is transmitted equally to all portions of the fluid and to the walls of its container. This means that when a driver exerts force on the brake pedal, this force is transmitted through the brake fluid to create equal pressure and force at each of the wheel cylinders, effectively applying the brakes.