Advertisements
Advertisements
Question
The diagram below in Fig. 4.12 shows a device which makes the use of the principle of transmission of pressure.

- Name the parts labelled by the letters X and Y.
- Describe what happens to valves A and B and to the quantity of water in the two cylinders when the lever arm is moved down.
- Give reasons for what happens to valves A and B in part (ii).
- What happens when the release valve is opened?
- What happens to valve B in cylinder P when the lever arm is moved up?
- Give a reason for your answer in part (v).
- State one use of the above device.
Advertisements
Solution
- X : Press Plunger; Y: Pump Plunger
- When the lever is moved down, valve B closes and valve A opens, so the water from cylinder P is forced into cylinder Q.
- Valve B closes due to an increase in pressure in cylinder P. This pressure is transmitted to the connecting pipe and when the pressure in connecting pipe becomes greater than the pressure in cylinder Q, valve A opens up.
- When the release valve is opened, the ram (or press) plunger Q gets lowered and water of cylinder Q runs out in the reservoir.
- When the lever arm is moved up valve B opens upwards.
- When the lever arm is moved up valve B opens upward because the pressure in cylinder P decreases.
- An hydraulic press is used for pressing cotton bales and goods like quilts, books, etc.
RELATED QUESTIONS
State whether the following statement is true or false :
The buoyant force depends on the nature of object immersed in the liquid
Why do we feel light on our feet when standing in a swimming pool with water up to our armpits ?
The weight of a body is more than the buoyant force experienced by it, due to a liquid. The body will
How does the pressure exerted by a solid and fluid differ?
Complete the following sentence :
Pressure of a liquid at a given depth is .................. To the density of the liquid.
What is the cause of upthrust? At which point can it be considered to act?
A body experiences an upthrust F1 in river water and F2 in sea water when dipped up to the same level. Which is more, F1 or F2? Give reason.
Complete the following sentence :
A piece of wood is held under water. The upthrust on it will be ___________ the weight of the wood piece.
You are provided with a hollow iron ball A of volume 15 cm3 and mass 12 g and a solid iron ball B of mass 12 g. Both are placed on the surface of water contained in a large tub.
- Find upthrust on each ball.
- Which ball will sink? Give a reason for your answer (Density of iron = 8.0 g cm-3)
Figure shows the same block of wood floating in three different liquids A, B and C of densities ρ1, ρ2 and ρ3 respectively. Which of the liquid has the highest density? Give a reason for your answer.

