MCQS
1. Why do we not normally feel atmospheric pressure?
a) Because it is very low b) Because it is very high c) Because practically all bodies contain air inside them d) Because we live in air
2. According to Pascal’s law, pressure applied to an enclosed fluid is:
a) Increased and applied to every part of the fluid b) Reduced and transmitted to the container walls c) Transmitted unchanged to every part of the fluid and the walls of its container d) Increased in proportion to the fluid’s mass and then transmitted to each part
3. What provides electrical connections to the coil of a galvanometer?
a) A thin spring b) A thick wire c) A resistor d) A capacitor
4. How many commonly recognised states of matter are there?
a) 2 b) 3 c) 4 d) 5
5. According to Hooke’s law, within the elastic limit, the applied force is directly proportional to:
a) Length b) Extension or compression c) Weight d) Area
6. The masses of equal volumes of different substances are compared by considering what?
a) The number of molecules in that volume b) The total mass of molecules in that volume c) The size of the molecules d) The distance between molecules
7. Which of the following are applications of Hooke’s law?
a) Spring scales b) Balance wheels in mechanical clocks c) Galvanometers d) All of these
8. The force produced by pressure on a surface acts at what angle to the surface?
a) Parallel b) Perpendicular c) Oblique d) None of these
9. A block has a surface 50 cm long and 40 cm wide. What force does atmospheric pressure of 100 kPa exert on it?
a) 20 kN b) 100 kN c) 200 kN d) 500 kN
10. Liquid pressure depends on:
a) Depth only b) Density of the liquid only c) Both the depth and density of the liquid d) Weight only
11. What type of change occurs when a material is stretched beyond its elastic limit?
a) Temporary b) Permanent c) Reversible d) Elastic
12. Why is a sharp-ended wooden stick easier to push into the ground?
a) The force is greater b) The force acts over a larger area c) The force is concentrated over a small area d) The force is applied parallel to the surface
13. Which formula gives pressure?
a) P = F × A b) P = F + A c) P = F − A d) P = F/A
14. Which property enables a material to regain its original shape after the force is removed?
a) Plasticity b) Elasticity c) Hardness d) Weakness
15. Which instrument is used to measure atmospheric pressure?
a) Hydrometer b) Thermometer c) Barometer d) Anemometer
16. The forces of attraction responsible for the states of matter act between:
a) Atoms and molecules b) Protons and neutrons c) Electrons and protons d) Atoms and atoms
17. The elastic limit is represented in which type of graph in this chapter?
a) Force graph b) Extension graph c) Load–extension graph d) Spring-constant graph
18. Why do heavy animals such as elephants have thick legs and broad feet?
a) To improve their appearance b) To increase their weight c) The larger contact area reduces pressure d) To help them run faster
19. Why is the tip of a thumb pin sharp and pointed?
a) To improve its appearance b) To increase the contact area c) To decrease the contact area d) To reduce its weight
20. What does the spring constant indicate?
a) Spring length b) Spring width c) Spring stiffness d) Spring weight
21. Two plates with areas of 2 m² and 3 m² are placed at the same depth in a liquid. What is the ratio of pressure on them?
a) 1:1 b) 2:3 c) 3:2 d) 4:9
22. Which formula is used to calculate the spring constant?
a) k = F + x b) k = F − x c) k = F/x d) k = F × x
23. What happens to atmospheric pressure as altitude above Earth’s surface increases?
a) It increases b) It decreases c) It remains unchanged d) It first increases and then decreases
24. How does liquid pressure change as depth increases?
a) It increases b) It decreases c) It remains unchanged d) It first increases and then decreases
25. What motion is controlled by the springs in the balance wheel of a mechanical clock?
a) Back-and-forth motion b) Speed c) Size d) Shape
26. Pressure is defined as:
a) Force applied parallel to a unit area b) Force applied perpendicularly per unit area c) Force applied to the total area of an object d) Force applied to the total mass of an object
27. What happens when a tennis ball is struck by a racket?
a) The ball deforms b) The racket strings deform c) Both deform d) Neither changes
28. If the experiment is repeated with a stiffer spring, what happens to the slope of the load–extension graph?
a) It decreases b) It increases c) It remains unchanged d) The graph becomes curved
29. What changes can a force produce in an object?
a) No change b) A change in size only c) A change in shape only d) A change in both size and shape
30. What is the SI unit of pressure?
a) N m b) N m² c) N/m d) N/m²
31. Four wires made of the same material are stretched by equal loads. Which wire will elongate the most?
a) Length 1 m, diameter 1 mm b) Length 2 m, diameter 2 mm c) Length 3 m, diameter 3 mm d) Length 4 m, diameter 0.5 mm
32. What is the approximate value of standard atmospheric pressure?
a) 1.013 × 10³ N m⁻² b) 1.013 × 10⁵ N m⁻² c) 1.013 × 10⁷ N m⁻² d) 1.013 × 10⁹ N m⁻²
33. What do liquids exert in all directions?
a) Force b) Pressure c) Volume d) Density
34. Hydraulic presses and vehicle hydraulic brakes operate according to:
a) Hooke’s law b) Pascal’s law c) Newton’s law d) Archimedes’ principle
35. What happens if the force applied to a spring exceeds its elastic limit?
a) It becomes permanently deformed b) It returns to its original shape c) It becomes stiffer d) It breaks in every case
36. The extension of the spring in a common spring scale indicates the:
a) Length b) Weight c) Width d) Thickness
37. Density can be used as a test of a substance’s:
a) Weight b) Purity c) Length d) Width
38. What is the shape of the load–extension graph for an elastic solid within its proportional limit?
a) Curved b) Straight line c) Irregular d) Circular
39. What is the SI unit of the spring constant?
a) N m b) N/m c) N s d) N m²
40. Why are knives and blades kept sharp?
a) To make cutting easier b) To improve their appearance c) To reduce their weight d) To increase their length
41. What is a force that changes an object’s size or shape called?
a) Tensile force b) Compressive force c) Deforming force d) Elastic force
42. The limit up to which most materials behave elastically is called the:
a) Breaking limit b) Elastic limit c) Hardness limit d) Extension limit
43. A straight-line force–extension graph for a spring passes through the:
a) End point b) Origin c) Middle point d) Any point
44. In the equation F = kx, what does k represent?
a) Force constant b) Length constant c) Spring constant d) Mass constant
45. A change in atmospheric pressure in an area may indicate a change in:
a) Temperature b) Weather c) Wind speed d) Wind direction
46. Spring scales are used to measure the:
a) Length of objects b) Weight of objects c) Volume of objects d) Density of objects
47. When an external force acts on an object, it may change its:
a) Size b) Shape c) Size or shape d) Neither size nor shape
48. What happens to pressure when the contact area decreases while force remains constant?
a) It decreases b) It increases c) It remains unchanged d) It first decreases and then increases
49. What form of energy is stored in a compressed spring?
a) Kinetic energy b) Potential energy c) Internal energy d) Heat energy
50. Why is a thick-ended wooden stick more difficult to drive into the ground?
a) The force is smaller b) The force acts over a larger area c) The force acts over a smaller area d) The force is not perpendicular
51. Density is defined as:
a) Force per unit area b) Mass per unit volume c) Volume per unit mass d) Force per unit length
52. Building designers and engineers pay special attention to the density of:
a) Wood only b) Water c) Construction materials d) Air
53. Liquid pressure at a point is proportional to the:
a) Density of the liquid b) Depth below the liquid surface c) Acceleration due to gravity d) All of the above
54. Which statement correctly describes pressure in everyday situations?
a) Pressure decreases as force increases b) Pressure increases as area increases c) Pressure increases as area decreases d) Pressure increases as force decreases
55. A galvanometer is used to detect the:
a) Voltage b) Resistance c) Presence of electric current d) Power
56. The density of a substance is equal to:
a) The mass of its unit volume b) The volume of its unit mass c) Its total mass d) Its total volume
57. Which is the SI unit of density?
a) kg/m³ b) g/cm³ c) N/m² d) J/s
58. An object that returns to its original size and shape after the deforming force is removed is called:
a) Inelastic b) Elastic c) Plastic d) Rubber
59. The slope of a force–extension graph is equal to the:
a) Force b) Extension c) Spring constant k d) Weight
60. What is the approximate length of the glass tube in a simple mercury barometer?
a) Half a metre b) One metre c) Two metres d) Three metres
61. Hooke’s law is applied in the working of which instruments or devices?
a) Spring scale b) Galvanometer c) Balance wheel of a mechanical clock d) All of these
62. Does the atmosphere exert pressure?
a) No b) Yes c) Sometimes d) Only at high altitudes
63. Atmospheric pressure is present up to approximately what altitude?
a) 50 km b) 100 km c) 150 km d) 200 km
64. A wire is stretched by a weight W. If its diameter is reduced to half, how does its extension change?
a) Becomes half b) Doubles c) Becomes one-fourth d) Becomes four times
65. A hydraulic press works on the:
a) Hooke’s law b) Pascal’s law c) Principle of conservation of energy d) Principle of conservation of momentum
66. The density of iron is 7.8 g cm⁻³. What is this value in kg m⁻³?
a) 7800 kg m⁻³ b) 780 kg m⁻³ c) 78 kg m⁻³ d) 7.8 kg m⁻³
67. Why can walking on pebbles be painful?
a) Our weight increases b) The contact area decreases c) The contact area increases d) The force becomes smaller
68. Hooke’s law applies, within the elastic limit, to:
a) A thin straight metal wire b) A rubber band c) Both of these d) Neither of these
69. Pascal’s law is applied in a:
a) Hydraulic system b) Electrical system c) Mechanical system d) Optical system
Short Questions
(1) Explain how a manometer works and mention one of its applications.
(2) Why do we not normally feel atmospheric pressure? Explain.
(3) Define an elastic object and give an example.
(4) State Hooke’s law and write its mathematical expression.
(5) What is the effect of a leak in the sealed end of the glass tube of a simple barometer?
(6) What is meant by a deforming force? Explain with an example.
(7) State Pascal’s law and give one application.
(8) Why do football and hockey boots have studs on their soles?
(9) How does atmospheric pressure vary with altitude?
(10) Why do heavy animals such as elephants have broad feet?
(11) How can the volume of a regularly shaped solid be calculated?
(12) Explain the relationship among mass, volume, and density.
(13) What is the function of the hairspring in a galvanometer?
(14) Explain why atmospheric pressure decreases as altitude above Earth’s surface increases.
(15) Why is steel used to make springs instead of iron?
(16) Define the spring constant and write the formula used to calculate it.
(17) Why do fast-running animals such as deer have a small contact area under their feet?
(18) Why does a giraffe’s long neck not cause difficulty when it raises or moves it suddenly?
(19) Give everyday examples that demonstrate pressure, such as a knife and a thumb pin.
(20) Compare the water pressure one metre below the surface of a swimming pool with that one metre below the surface of a large, deep lake.
(21) Why must building designers and engineers consider the density of construction materials?
(22) Explain pressure in liquids and derive its formula.
(23) What happens when immiscible liquids of different densities are poured together?
(24) Define pressure and write its mathematical formula.
(25) How can density be used to test the purity of a substance?
(26) Why do elephants have thick legs and broad feet?
(27) What is meant by deformation of solids?
(28) Using everyday examples, explain how pressure depends on force and area.
(29) Describe the applications of Hooke’s law in spring scales, galvanometers, and the balance wheel of a mechanical clock.
(30) Describe experiments that demonstrate that the atmosphere exerts pressure.
(31) Describe the main features of the force–extension graph.
(32) State the basic principle on which automobile hydraulic brakes operate.
(33) If air is trapped above the mercury column in a barometer instead of a vacuum, how will the mercury-column height be affected?
(34) Explain how changes in atmospheric pressure can indicate changes in weather.
(35) State the SI unit of density and one commonly used alternative unit.
(36) Define atmospheric pressure.
(37) Explain the principle used to measure atmospheric pressure with a simple mercury barometer.
(38) What is the relationship between liquid pressure and depth?
(39) Explain the function of the balance wheel in a mechanical clock.
(40) If pressure is increased at one point in a confined liquid, what happens to the pressure throughout the liquid? Give a daily-life application.
(41) Draw and explain the load–extension graph for an elastic solid.
(42) Why is it painful to walk barefoot on pebbles?
(43) Explain how liquid pressure varies with depth.
(44) Define elastic limit and explain why it is important.
(45) State Hooke’s law. Does a material remain elastic beyond its elastic limit? Give a reason.
(46) Differentiate between force and pressure.
(47) Explain the relationship between pressure, force, and area using a wooden stick as an example.
(48) Explain the working principle of a spring scale.
(49) Define standard atmospheric pressure and state its value.
(50) State Pascal’s law and explain its applications in hydraulic presses and vehicle brakes.
(51) Define the elasticity of a solid.
(52) Define density and write its formula.
(53) Define inelastic materials and give examples.
(54) Comment on the statement: “Density is a property of a material, not of the object made from it.”
(55) How can an engineer estimate the load of a large structure?
(56) Explain how atmospheric pressure is measured using a barometer.
(57) Which is more elastic in each pair: (a) iron or rubber, and (b) air or water?
(58) Explain how forces can change the size or shape of an object.
(59) Explain why pressure on a surface produces a force perpendicular to that surface.
(60) Why do different substances have different densities?
(61) Explain the working and application of a liquid barometer.
Long Questions
1. On which factors does the pressure exerted by a liquid depend? Explain how it can be calculated.
2. Describe the working of a hydraulic press and hydraulic brakes.
3. Define density and explain how it differs among various materials.
4. A brick measures 5 cm × 10 cm × 20 cm and has a mass of 5 kg. Calculate the maximum and minimum pressure it can exert on a horizontal surface.
5. A hydraulic lift has a small piston of area 0.01 m² and a large piston of area 1.0 m². If a force of 500 N is applied to the smaller piston, calculate the force exerted by the larger piston.
6. In a car’s hydraulic braking system, a normal force of 500 N acts on a piston with a cross-sectional area of 5 cm². Calculate (a) the pressure transmitted to the brake oil and (b) the force on a second piston of area 20 cm².
7. Derive the formula for pressure in a liquid and explain its significance.
8. Explain how the atmosphere exerts pressure. Describe at least three applications or examples of atmospheric pressure.
9. Explain the working of a barometer with a labelled diagram.
10. A force of 500 N acts normally on a piston of a car’s hydraulic braking system with a cross-sectional area of 5 cm². Calculate (a) the pressure transmitted to the brake oil and (b) the force on a brake piston of cross-sectional area 20 cm².
11. State Hooke’s law and describe three applications of it.
12. A cylindrical water tank is installed 20 m above ground level on a building. The water depth in the tank is 2 m. Calculate the pressure at ground level.
13. An iron block is 3 cm long, 2 cm wide, and 2 cm thick. If its mass is 94 g, calculate its density.
14. The mass of 5 litres of milk is 4.5 kg. Calculate its density in SI units.
15. State Pascal’s law, explain it, and describe its applications.
16. The pressure in a hydraulic press is increased by 10 N cm⁻². Calculate the additional load supported by an output platform with a cross-sectional area of 50 cm².
17. Explain Hooke’s law using an experiment and a graph.
18. A solid of mass 60 g is placed in a measuring cylinder, causing the water level to rise from 40 cm³ to 44 cm³. Calculate the density of the solid.
19. Explain pressure and give examples from everyday life.
20. The small and large pistons of a hydraulic press have cross-sectional areas of 10 cm² and 100 cm², respectively. What force must be applied to the small piston to lift a car weighing 4000 N?
21. Calculate the water pressure on a deep-sea diver at a depth of 10 m. The density of seawater is 1030 kg m⁻³.
22. A block has a density of 8 × 10³ kg m⁻³ and a volume of 60 cm³. Calculate its mass.
23. The diameters of the small and large pistons of a hydraulic press are 5 cm and 25 cm, respectively. If a force of 160 N is applied to the smaller piston, calculate the weight lifted by the larger piston.
24. A spring extends by 20 mm under a load of 40 N. Calculate its spring constant. Also find the weight of an object that produces an extension of 16 mm.
25. At sea level, what height would a barometer’s liquid column reach if mercury were replaced by water of density 1000 kg m⁻³? Take the density of mercury as 13.6 × 10³ kg m⁻³.
26. Discuss different applications of Hooke’s law.
27. Describe the working and applications of a simple mercury barometer and a manometer.
28. State Pascal’s law and explain its applications with examples.
Answer Key
1. Because practically all bodies contain air inside them.
2. Transmitted unchanged to every portion of the fluid and the walls of the containing vessel.
3. A thin spring.
4. 3.
5. Extension or compression.
6. The total mass of molecules in that volume.
7. All of these.
8. Perpendicular.
9. 20 kN.
10. Depth and density of the liquid.
11. Permanent change.
12. The force is concentrated over a small area.
13. P = F/A.
14. Elasticity.
15. Barometer.
16. Atoms and molecules.
17. Load–extension graph.
18. The larger contact area reduces pressure.
19. To decrease the contact area.
20. Spring stiffness.
21. 1:1.
22. k = F/x.
23. Decreases.
24. Increases.
25. Back-and-forth motion.
26. Force applied perpendicularly per unit area.
27. Both deform.
28. The slope increases.
29. A change in both size and shape.
30. The source answer key appears to contain a unit-formatting error; the SI unit of pressure is N/m² (Pa).
31. Length 4 m, diameter 0.5 mm.
32. 1.013 × 10⁵ N m⁻².
33. Pressure.
34. Pascal’s law.
35. It becomes permanently deformed.
36. Weight.
37. Purity.
38. Straight line.
39. N/m.
40. To make cutting easier.
41. Deforming force.
42. Elastic limit.
43. Origin.
44. Spring constant.
45. Change in weather.
46. Weight of objects.
47. Size or shape.
48. Increases.
49. Potential energy.
50. The force acts over a larger area.
51. Mass per unit volume.
52. Construction materials.
53. All of the above (as listed in the source key).
54. Pressure increases as area decreases.
55. Presence of electric current.
56. The mass of its unit volume.
57. kg/m³.
58. Elastic.
59. Spring constant k.
60. One metre.
61. All of these.
62. Yes.
63. 100 km (as given in the source key).
64. Four times.
65. Pascal’s law.
66. 7800 kg m⁻³.
67. The contact area decreases.
68. Both.
69. Hydraulic system.