Which types of brakes are commonly used on trailers?

The correct answer focuses on the types of brake systems commonly employed in trailers, which include electric and hydraulic brakes. Electric brakes utilize an electromagnetic system that activates the brakes of the trailer when the towing vehicle's brake pedal is pressed. This system is particularly favored for its efficiency and reliability, especially in applications where quick stops are necessary. Hydraulic brakes operate through fluid pressure generated by the towing vehicle's braking system, offering strong stopping power and the advantage of being self-adjusting, which maintains consistent performance even as components wear over time.

Both of these brake types are prevalent due to their effectiveness in various conditions and their ability to handle the additional weight that trailers often carry. These systems enhance the safety and control of towing vehicles.

Other types listed, such as pneumatic and mechanical brakes, are less common in typical trailer setups. Pneumatic brakes, which rely on air pressure, are mainly used in large commercial vehicles. Mechanical brakes might involve direct cable or lever actions, but are not typically found in the modern productivity needed for trailer operations. Disc and drum, while relevant in describing types of brake configurations, do not specifically categorize the operational technology used in trailer braking systems.