In magnitude hydraulic stress is equal to 

Explanation:

Hydraulic stress refers to the force exerted per unit area within a fluid. It is a measure of how much pressure is applied across the surface of a material or fluid in a hydraulic system.

• Hydraulic Force refers to the total force applied by the fluid, but it is not a direct measure of stress.
• Hydraulic Pressure is the correct answer because pressure is defined as force per unit area, which directly corresponds to hydraulic stress.
• Restoring Force generally refers to the force that brings a system back to equilibrium, and it's not directly related to hydraulic stress.
• Hydraulic Strain refers to the deformation caused by pressure but doesn't measure the magnitude of stress directly.

Final Answer

The correct answer is hydraulic pressure.