Final Answer:
In air-operated disc brakes, air pressure acts on a brake chamber and slack adjuster like S-Cam brakes, but instead of the S-Cam, a power screw is used. Option B is the answer.
Step-by-step explanation:
Air-operated disc brakes share similarities with S-Cam brakes in terms of the brake chamber and slack adjuster configuration. In both systems, air pressure from the brake chamber is transmitted to the slack adjuster, facilitating the adjustment of brake shoe clearance. However, the key difference lies in the mechanism used for this adjustment.
While S-Cam brakes employ a rotating S-Cam to push the brake shoes into contact with the drum, air-operated disc brakes utilize a power screw. The power screw converts the linear motion produced by the air pressure into the rotational force needed to adjust the clearance between the brake pads and the disc, ensuring efficient and reliable braking performance.
Option B is the answer.