When blood pressure is measured, the cuff of the sphygmomanometer is wrapped round the upper arm and must be held at the level of the heart. Why?

• Blood pressure depends on the level of the blood.

• Blood pressure is normal when the cuff and heart are at the same level.

• Blood is able to flow easily to the wrist.

The pressure of sea water at the bottom of the sea is 1.2 × 108 N m–2.

Determine the depth of the sea.

[Density of sea water = 1020 kg m^–3]

• 1.18×10⁴ m

• 1.18×10⁵ m

• 1.18×10⁶ m

• 1.18×10⁹ m

Diagram shows a U-tube filled with two liquids, X and Y which are immiscible. The heights of the liquid columns of X and Y from level P are 8 cm and 4 cm respectively. Which of the following statements is true?

• The density of X is less than the density of Y.

• The liquid pressure is higher in column X than in column Y at level P.

• The densities of liquids X and Y are equal.

Diagram shows the design of a dam. Why does the thickness of the dam increase with its depth?

• The design of this structure is stronger.

• Water pressure increases with depth.

• The cost of construction is lower.

• Water pressure acts uniformly in all directions.

A submarine has a surface area of 300 m².

The density of sea water is 1050 kg m^–3.

At what depth under the sea, will the additionalpressure on the submarine be 5 × 10⁵ Pa?

[Take g = 10 N kg^–1]

• 47.62 m

• 67.62 m

• 87.62 m

• 57.62 m

The figure below shows a reservoir on a hill. The reservoir supplies water to a water tank on a tall building.

Calculate the water pressure at X.

(Density of water = 1000 kg m^–3)

• 1.4×10⁹ Nm^–2

• 1.4×10² Nm^–2

• 1.4×10⁵ Nm^–2

• 1.4×10⁸ Nm^–2

A coin sinks to a depth of 5 m in a liquid of density 800 kg m^–3. At what depth, in a different liquid of density 600 kg m^–3, will the coin be subjected to the same pressure?

• 6.67 m

• 8.67 m

• 9.67 m

• 5.67 m

The figure shows a pond with two fish P and Q.

What is the correct relation of the water pressures on fish P and fish Q?

• Water pressure on fish Q > Water pressure on fish P.

• Water pressure on fish Q < Water pressure on fish P.

• Water pressure on fish Q = Water pressure on fish P.