Q2) The diagram given below show a device)
a) Name the device.
b) What is it used for?
c) What is the difference between the two
diagrams? State the reason behind it.
Answers
Answer:
The given diagram is the set up of a hydraulic press. It is commonly known as Bramah press, which works on the principle of Pascal's law.
(i) The parts labelled X and Y are two hollow cylinders fitted with valves A and B respectively at the bottom.
(ii) When a small force is applied on the pump plunger A, we can lift ta large weight kept on the press plunger B. However, if no weight is kept on B, it rises up against a fixed roof with force F
2
=F
1
×
A
1
A
2
.
(iii) When the pump plunger A is raised by the handle, Valve V1 opens and water from the supply tank is pushed up by the atmospheric pressure into the cylinder M. As piston A is pushed down by lowering the handle, valve V1 closes due to increase in pressure in the cylinder M. The pressure R is more than in cylinder L and the valve V2 opens. The water from M gets forced into L and piston B is raised against fixed roof and the bale of cotton is pressed.
(iv) When the function of the machine is over, the release valve V3 is opened and the press plunger B gets lowered. The water from L runs out into the water supply tank.
(v) The cylinder P and valve B is unclear in the question and hence cannot be answered.
(vi) This is not answered as part (v) is not answerable.
(vii) Uses of Hydraulic press - It is used for pressing cotton bales, quilts, books, extracting juice from sugarcane, squeezing the oil out of seeds, etc.
Below is the diagrammatic representation.