The properties of matter explain how solids, liquids, and gases behave under different conditions. This chapter covers elasticity, stress and strain, Hooke’s law, pressure in fluids, Pascal’s principle, density, and buoyancy. It also discusses practical applications such as hydraulic systems and floating bodies. The MCQs below help students test their understanding of these key concepts.
1. Which property allows a material to regain its shape after deformation?
- A. Elasticity ✅
- B. Plasticity
- C. Brittleness
- D. Hardness
Explanation: Elasticity is the ability of a material to return to its original shape after the deforming force is removed.
2. Hooke’s law relates:
- A. Stress and strain ✅
- B. Mass and volume
- C. Pressure and volume
- D. Force and time
Explanation: Hooke’s law states that stress is directly proportional to strain within the elastic limit.
3. The SI unit of stress is:
- A. Pascal ✅
- B. Newton
- C. Joule
- D. Watt
Explanation: Stress is measured in pascals (N/m²).
4. Density is defined as:
- A. Mass per unit volume ✅
- B. Weight per unit volume
- C. Mass per unit area
- D. Volume per unit mass
Explanation: Density = Mass ÷ Volume, measured in kg/m³.
5. The principle used in hydraulic brakes is:
- A. Pascal’s principle ✅
- B. Archimedes’ principle
- C. Bernoulli’s principle
- D. Principle of moments
Explanation: Pascal’s principle states that pressure applied to an enclosed fluid is transmitted equally in all directions.
6. Which principle explains why objects float?
- A. Archimedes’ principle ✅
- B. Pascal’s principle
- C. Bernoulli’s principle
- D. Principle of inertia
Explanation: Archimedes’ principle states that an object immersed in a fluid experiences an upward buoyant force equal to the weight of the displaced fluid.
7. Pressure in a liquid increases with:
- A. Depth ✅
- B. Temperature
- C. Surface area
- D. Volume
Explanation: Pressure in a liquid is given by P = ρgh, where h is the depth.
8. The SI unit of pressure is:
- A. Pascal ✅
- B. Newton
- C. Joule
- D. Watt
Explanation: 1 Pascal = 1 N/m².
9. Which quantity remains constant in an incompressible fluid?
- A. Density ✅
- B. Pressure
- C. Temperature
- D. Volume
Explanation: In incompressible fluids, density does not change with pressure.
10. The upward force experienced by an object in a fluid is called:
- A. Buoyant force ✅
- B. Lift force
- C. Frictional force
- D. Drag force
Explanation: Buoyant force is the upward thrust exerted by a fluid.
11. Which property of gases allows them to be compressed easily?
- A. Large intermolecular spaces ✅
- B. High density
- C. Strong bonding
- D. Elasticity
Explanation: Gases have large spaces between molecules, making them highly compressible.
12. An instrument used to measure liquid pressure is:
- A. Manometer ✅
- B. Barometer
- C. Hydrometer
- D. Voltmeter
Explanation: A manometer measures the pressure of a gas or liquid.
13. The pressure at the same depth in a liquid:
- A. Is the same in all directions ✅
- B. Is greater upward
- C. Is greater downward
- D. Varies randomly
Explanation: According to Pascal’s principle, pressure is transmitted equally in all directions.
14. The density of pure water at 4°C is:
- A. 1000 kg/m³ ✅
- B. 1 kg/m³
- C. 10 kg/m³
- D. 0.1 kg/m³
Explanation: Water has maximum density at 4°C.
15. Which property of liquids enables hydraulic systems to work?
- A. Incompressibility ✅
- B. High viscosity
- C. Low density
- D. Elasticity
Explanation: Hydraulic systems rely on the incompressibility of liquids to transmit force.