Question 4
In a vehicle's braking system, why is the force on the brake pads greater than the force the driver applies with the foot?
The right answer is the one marked above.
Because the slave cylinder has a larger cross-section than the master cylinder. The pressure is transmitted unchanged, so where the area is larger the force is larger.
Neither the length of the line nor the amount of oil increases the force. It is settled by the ratio of the two cross-sections alone.