Physics
Name and state the principle on which a hydraulic press works. Write one use of the hydraulic press.
Answer
A hydraulic press works on the principle of Pascal's law.
Principle — When a force F1 is applied on the piston A, it exerts a pressure on liquid contained in the cylinder P. According to Pascal's law, this pressure is transmitted through liquid in tube R to the piston B of the other cylinder Q due to which the piston B tends to move upwards.
Since, the area of cross section of cylinder P is less than that of the cylinder Q, therefore by applying a small force on the piston A, we can lift a large weight kept on the piston B.
When no weight is placed on the piston B, it rises up against a fixed roof with a force F2 (F2 > F1). If a bale of cotton is kept on the press plunger B, it gets compressed.
Use of hydraulic press — It is used for pressing cotton bales and goods such as books, quilts etc.
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