Q1
Define the term thrust. State its S.I. unit.
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Q2
What is meant by pressure? State its S.I. unit.
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Q3
(a) What physical quantity is measured in bar?
(b) How is the unit bar related to the S.I. unit pascal?
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(b) How is the unit bar related to the S.I. unit pascal?
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Q4
Define one pascal (Pa), the S.I. unit of pressure.
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Q5
State whether thrust is a scalar or vector?
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Q6
State whether pressure is a scalar or vector?
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Q7
Differentiate between thrust and pressure.
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Q8
How does the pressure exerted by a thrust depend on the area of surface on which it acts?
Explain with a suitable example.
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Q9
Why is the tip of an allpin made sharp?
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Q10
Explain the following:
(a) It is easier to cut with a sharp knife than with a blunt one.
(b) Sleepers are laid below the rails
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(a) It is easier to cut with a sharp knife than with a blunt one.
(b) Sleepers are laid below the rails
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Q11
What is a fluid?
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Q12
What do you mean by the term fluid pressure?
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Q13
How does the pressure exerted by a solid and a fluid differ?
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Q14
Describe a simple experiment to demonstrate that a liquid enclosed in a vessel exerts pressure
in all directions
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Q15
State three factors on which the pressure at a point in a liquid depends.
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Q16
Write an expression for the pressure at a point inside a liquid. Explain the meaning of the
symbols used.
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Q17
Deduce an expression for the pressure at a depth inside a liquid.
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Q18
How does the pressure at a certain depth in sea water differ from that at the same depth in
river water? Explain your answer.
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Q19
Pressure at free surface of a water lake is P1, while at a point at depth h below its free surface
is P2. (a) How are P1 and P2 related? (b) Which is more P1 or P2?
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Q20
Explain why a gas bubble released at the bottom of a lake grows in size as it rises to the surface
of lake.
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Q21
A dam has broader walls at the bottom than at the top. Explain.
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Q22
Why do sea divers need special protective suit?
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Q23
State the laws of liquid pressure.
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Q24
A tall vertical cylinder filled with water is kept on a horizontal table top. Two small holes A
and B are made on the wall of the cylinder, A near the middle and B just below the free
surface of water. State and explain your observation.
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Q25
How does the liquid pressure on a diver change if:
(i) The diver moves to the greater depth, and
(ii) The diver moves horizontally?
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(i) The diver moves to the greater depth, and
(ii) The diver moves horizontally?
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Q26
State Pascal’s law of transmission of pressure.
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Q27
Name two applications of Pascal’s law.
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Q28
Explain the principle of a hydraulic machine. Name two devices which work on this principle.
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Q29
Name and state the principle on which a hydraulic press works. Write one use of the hydraulic
press.
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Q30
The diagram in figure shows a device which makes use of the principle of transmission of
pressure.
(i) Name the parts labelled by the letters X and Y.
(ii) Describe what happens to the valves A and B and to the quantity of water in the two cylinders when the lever arm is moved down.
(iii) Give reasons for what happens to the valves A and B in part (ii).
(iv) What happens when the release valve is opened?
(v) What happens to the valve B in cylinder P when the lever arm is moved up?
(vi) Give a reason for your answer in part (v)
(vii) State one use of the above device.
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(i) Name the parts labelled by the letters X and Y.
(ii) Describe what happens to the valves A and B and to the quantity of water in the two cylinders when the lever arm is moved down.
(iii) Give reasons for what happens to the valves A and B in part (ii).
(iv) What happens when the release valve is opened?
(v) What happens to the valve B in cylinder P when the lever arm is moved up?
(vi) Give a reason for your answer in part (v)
(vii) State one use of the above device.
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Q31
Draw a simple diagram of a hydraulic jack and explain its working.
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Q32
Explain the working of a hydraulic brake with a simple labelled diagram.
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Q33
Complete the following sentences:
(a) Pressure at a depth h in a liquid of density ρ is ___________
(b) Pressure is ________ in all directions about a point in a liquid
(c) Pressure at all points at the same depth is _________
(d) Pressure at a point inside a liquid is __________ to its depth.
(e) Pressure of a liquid at a given depth is _______ to the density of liquid.
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(a) Pressure at a depth h in a liquid of density ρ is ___________
(b) Pressure is ________ in all directions about a point in a liquid
(c) Pressure at all points at the same depth is _________
(d) Pressure at a point inside a liquid is __________ to its depth.
(e) Pressure of a liquid at a given depth is _______ to the density of liquid.
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Multiple Choice type Questions
:
Q1
The S.I. unit of pressure is:
(a) N cm-2
(b) Pa
(c) N
(d) N m2
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(a) N cm-2
(b) Pa
(c) N
(d) N m2
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Q2
The pressure inside a liquid of density ρ at a depth h is:
(a) h ρ g
(b) h/ ρ g
(c) h ρ/ g
(d) h ρ
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(a) h ρ g
(b) h/ ρ g
(c) h ρ/ g
(d) h ρ
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Q3
The pressure P1 at a certain depth in river water and P2 at the same depth in sea water are
related as:
(a) P1 > P2
(b) P1 = P2
(c) P1 < P2
(d) P1 - P2 = atmospheric pressure
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(a) P1 > P2
(b) P1 = P2
(c) P1 < P2
(d) P1 - P2 = atmospheric pressure
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Q4
The pressure P1 at the top of a dam and P2 at a depth h from the top inside water
(density ρ) are related as:
(a) P1 > P2
(b) P1 = P2
(c) P1 - P2 = h ρ g
(d) P2 – P1 = h ρ g
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(a) P1 > P2
(b) P1 = P2
(c) P1 - P2 = h ρ g
(d) P2 – P1 = h ρ g
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