9_CH2-Fluid Mechanics and Thermal Physics

Which statement best defines pressure in physics?

• The total force acting tangentially on any surface

• The total force acting normally on the surface in contact

• The thrust acting on a unit area of the surface in contact

• The ratio of area to thrust

Using the formula Pressure = Thrust (T) / Area (A), what happens to pressure when the same thrust is applied to a smaller area?

• Pressure decreases

• Pressure remains the same

• Pressure becomes zero

• Pressure increases

Which of the following correctly lists units of pressure mentioned in the lesson?

• Nm, Pa, bar

• Nm², Pa, bar, millibar

• N/m², joule, bar

• Pa, watt, Nm²

A figure shows a fish surrounded by arrows pointing equally in all directions. Which law of liquid pressure does this diagram best represent?

• Pressure depends on depth

• Pressure is same in all directions about a point in a liquid

• Pressure depends on density

• Liquid finds its own level

When a manometer is moved back and forth at the same depth in a beaker of water, its reading does not change. What conclusion follows?

• Pressure varies horizontally at the same depth

• Pressure is same at all points in a horizontal plane in a liquid

• Pressure only depends on the vessel’s shape

• Pressure is greater near the container walls

Which statement best describes the fifth law of liquid pressure?

• Liquids exert no pressure at the surface

• Liquid pressure is maximum at the top

• Liquid finds its own level regardless of vessel shape

• Pressure depends only on temperature

Which formula gives the pressure at a point inside a liquid of density d at depth h under gravitational field g?

• P = h d g

• P = d/h

• P = g/h

• P = h/g

A vertical liquid column of cross-sectional area A and height h has volume Ah. Using mass = volume × density, what is the expression for the mass of this column?

• A/d

• A h d

• h/d

• A g h

Two points are located in the same liquid: Point X at depth 0.5 m and Point Y at depth 1.0 m. The liquid density is 1000 kg/m³ and g = 10 N/kg. Which statement is correct about the pressures at X and Y?

• Pressure at X equals pressure at Y.

• Pressure at X is greater than pressure at Y.

• Pressure at Y is greater than pressure at X.

• Pressures at both points are zero.

Which instrument uses a column of mercury to measure atmospheric pressure by the height of the mercury column?

• Aneroid barometer

• Simple mercury barometer

• Altimeter

• Thermometer