Class 9 Physics Full Book MCQs Quiz – All 9 Units (FBISE)

1. What is the SI base unit of mass?

1. Newton
2. Tonne
3. Kilogram
4. Gram

2. Which is a derived quantity?

1. Mass
2. Speed
3. Length
4. Time

3. How many significant figures are in 0.00450?

1. 2
2. 4
3. 5
4. 3

4. What is 3.2 mm in metres?

1. 0.00032 m
2. 3200 m
3. 0.0032 m
4. 0.032 m

5. Which instrument is best suited to measuring the diameter of a thin wire?

1. Measuring cylinder
2. Micrometer screw gauge
3. Metre rule
4. Stopwatch

6. What is 720 000 in standard scientific notation?

1. 7.2 × 10⁴
2. 0.72 × 10⁵
3. 7.2 × 10⁵
4. 72 × 10⁵

7. Which quantity has both magnitude and direction?

1. Speed
2. Distance
3. Time
4. Velocity

8. What does the slope of a velocity–time graph represent?

1. Displacement
2. Speed
3. Acceleration
4. Distance

9. A body starts from rest and accelerates at 3 m/s² for 4 s. How far does it travel?

1. 48 m
2. 6 m
3. 24 m
4. 12 m

10. Ignoring air resistance, what happens to the speed of a freely falling stone?

1. It becomes zero after one second
2. It increases at a constant rate
3. It stays constant
4. It decreases at a constant rate

11. What net force accelerates a 5 kg object at 2 m/s²?

1. 2.5 N
2. 7 N
3. 0.4 N
4. 10 N

12. What is the momentum of a 3 kg object moving east at 4 m/s?

1. 0.75 kg·m/s east
2. 12 kg·m/s east
3. 12 kg·m/s west
4. 7 kg·m/s east

13. What is the weight of a 6 kg object where g = 10 N/kg?

1. 0.6 N
2. 16 N
3. 60 N
4. 6 N

14. A 20 N force acts perpendicularly 0.3 m from a pivot. What is its moment?

1. 20.3 N·m
2. 0.015 N·m
3. 6 N·m
4. 60 N·m

15. What is required for rotational equilibrium?

1. Zero mass
2. A constant nonzero resultant moment
3. A clockwise moment only
4. Zero resultant moment

16. What is a couple?

1. Two equal forces acting along the same line in opposite directions
2. Two perpendicular forces acting at one point
3. A force acting through a pivot
4. Two equal opposite parallel forces with different lines of action

17. Which conditions are needed for a rigid body to be in static equilibrium?

1. At rest with zero resultant force only
2. At rest with equal parallel forces acting in the same direction
3. At rest with zero resultant force and zero resultant moment
4. At rest with zero resultant moment only

18. A force of 200 N acts uniformly perpendicular to an area of 0.04 m². What pressure does it exert?

1. 50 Pa
2. 5000 Pa
3. 800 Pa
4. 8 Pa

19. What is the SI unit of pressure?

1. Watt
2. Newton
3. Pascal
4. Joule

20. A spring extends 0.05 m under 10 N. What is its spring constant?

1. 0.5 N/m
2. 20 N/m
3. 0.005 N/m
4. 200 N/m

21. What happens after a load is removed from an elastically deformed solid?

1. Its mass increases
2. Its volume always doubles
3. It returns to its original shape
4. It remains permanently stretched

22. A 15 N force moves a box 4 m in the direction of the force. How much work does it do?

1. 0 J
2. 60 J
3. 19 J
4. 3.75 J

23. What is the kinetic energy of a 2 kg body moving at 6 m/s?

1. 12 J
2. 72 J
3. 6 J
4. 36 J

24. A machine does 900 J of work in 3 s. What is its average power?

1. 30 W
2. 300 W
3. 2700 W
4. 903 W

25. When a falling object speeds up without air resistance, what happens to its energy?

1. Both kinetic and gravitational potential energy decrease
2. Gravitational potential energy changes into kinetic energy
3. Kinetic energy changes into gravitational potential energy
4. Total mechanical energy increases

26. A block has a mass of 240 g and a volume of 80 cm³. What is its density?

1. 0.33 g/cm³
2. 160 g/cm³
3. 19 200 g/cm³
4. 3 g/cm³

27. What is 2 g/cm³ in kg/m³?

1. 20 kg/m³
2. 0.002 kg/m³
3. 2000 kg/m³
4. 200 kg/m³

28. What is 27 °C approximately on the Kelvin scale?

1. 246 K
2. 273 K
3. 27 K
4. 300 K

29. Which property determines the direction of net heat transfer between objects in contact?

1. Volume difference
2. Density difference
3. Temperature difference
4. Mass difference

30. Which pair of poles attracts?

1. North and north
2. South and south
3. Two identical poles
4. North and south

31. What happens when a bar magnet is cut into two pieces?

1. Only one piece remains magnetic
2. Both pieces must lose all magnetism
3. Each piece has both a north and a south pole
4. One piece has only a north pole and one only a south pole

32. Outside a bar magnet, which way do magnetic field lines point?

1. Inwards towards both poles
2. From north to south
3. From south to north
4. From the centre towards both poles

33. Which material is commonly used for a temporary electromagnet core?

1. Copper
2. Glass
3. Plastic
4. Soft iron

34. How can a coil's magnetic field generally be strengthened if its geometry and core stay fixed?

1. Disconnect the power supply
2. Reverse the current without changing its magnitude
3. Increase the current
4. Decrease the current

35. What does the north-seeking end of a small compass indicate at a point?

1. The strength of the field by its colour
2. The local magnetic field direction
3. The local gravitational field direction
4. The distance to the nearest magnet

36. Which is a testable hypothesis?

1. Springs are the most beautiful objects
2. Metal is always the best material
3. All experiments are enjoyable
4. Increasing the load increases a spring's extension within its proportional range

37. Why repeat measurements and calculate their mean?

1. To guarantee removal of zero error
2. To change the true value
3. To replace the need for units
4. To reduce the effect of random variation

38. Which principle governs the treatment of predictions that conflict with reliable evidence?

1. Keep the prediction and hide the results
2. Treat the prediction as proven
3. Reassess the prediction and the model behind it
4. Discard all observations

39. Which statement is an observation?

1. The liquid should boil soon
2. The thermometer reading rose from 22 °C to 30 °C
3. The liquid probably absorbed energy from the heater
4. The heater must be faulty

40. What is the best way to test the applicability of an explanation under new conditions?

1. Repeat the original conclusion without collecting data
2. Choose only the results that support it
3. Replace measurements with opinions
4. Make new predictions and test them

In the school lab, a student closes a micrometer before using it to measure a wire.

41. An instrument reads +0.02 mm when fully closed. What is the corrected value for a reading of 1.56 mm?

1. 1.58 mm
2. 1.56 mm
3. 0.02 mm
4. 1.54 mm

42. A student walks 10 m east and then 10 m west. What is the displacement?

1. 20 m west
2. 0 m
3. 20 m east
4. 10 m west

A road test records the car’s speed at the start and end of a six-second interval.

43. A car speeds up from 4 m/s to 16 m/s in 6 s. What is its average acceleration?

1. 72 m/s²
2. 2 m/s²
3. 3.3 m/s²
4. 12 m/s²

44. A cyclist travels 120 m in 15 s. What is the average speed?

1. 12 m/s
2. 0.125 m/s
3. 1800 m/s
4. 8 m/s

45. A passenger moves forward when a bus brakes suddenly. Which property explains this?

1. Pressure
2. Magnetism
3. Inertia
4. Elasticity

46. Which force pairs with a swimmer pushing water backwards?

1. Gravity pulls the swimmer downwards
2. The swimmer pushes water forwards
3. Air pushes the swimmer backwards
4. Water pushes the swimmer forwards

47. Why do seat belts reduce the force on a passenger during a collision?

1. They eliminate inertia
2. They increase stopping time
3. They increase the change in momentum
4. They increase the passenger's mass

48. A 2 kg trolley moving at 3 m/s sticks to a stationary 1 kg trolley. What is their common speed if external forces are negligible?

1. 1 m/s
2. 3 m/s
3. 6 m/s
4. 2 m/s

49. Where should you push to open a door with the least force?

1. Far from the hinge and along the door towards the hinge
2. Far from the hinge and perpendicular to the door
3. Near the hinge and perpendicular to the door
4. At the hinge

Students set up a horizontal balance beam with a pivot and apply downward forces on opposite sides.

50. A 30 N load is 0.4 m from a pivot. What force balances it 0.6 m away on the other side, with both forces perpendicular?

1. 18 N
2. 12 N
3. 20 N
4. 45 N

51. Which design generally makes a vehicle more stable?

1. A narrower base and the same centre of gravity
2. A lower centre of gravity and a wider base
3. A higher centre of gravity and a narrower base
4. A higher centre of gravity and the same base

52. Why does a sharp knife cut more easily than a blunt one under the same force?

1. Its edge applies pressure over a larger area
2. It reduces the pressure
3. It reduces the force to zero
4. Its edge applies pressure over a smaller area

A lab group hangs different loads from the same spring and compares the resulting extensions.

53. A spring extends by 2 cm under 4 N. What extension does 6 N produce within the proportional range?

1. 1 cm
2. 3 cm
3. 4 cm
4. 6 cm

54. A 4 kg bag is lifted 3 m where g = 10 N/kg. How much gravitational potential energy does it gain?

1. 12 J
2. 30 J
3. 120 J
4. 40 J

A workshop measures electrical energy supplied to a motor and the useful mechanical work produced.

55. A motor takes in 500 J and produces 350 J of useful work. What is its efficiency?

1. 30%
2. 50%
3. 85%
4. 70%

56. What work does the upward supporting force do on a bag carried horizontally at constant height?

1. Negative work
2. Work equal to its weight times the distance
3. Zero
4. Positive work

A student measures the volume of an irregular stone by water displacement.

57. A measuring cylinder reading rises from 32 mL to 47 mL when a stone is fully immersed. What is its volume?

1. 79 cm³
2. 15 cm³
3. 32 cm³
4. 47 cm³

A metal sample is heated in a lab. No material is added or lost.

58. A sample expands when heated and keeps the same mass. How does its density change?

1. It becomes zero
2. It decreases
3. It increases
4. It remains constant

A lab group measures spring extension after adding each of several different loads.

59. In a spring experiment, which variable is deliberately changed to see its effect on extension?

1. Type of ruler used
2. The written conclusion
3. Applied load
4. Measured extension

Two students plan a fair test of the relationship between load and spring extension.

60. Why keep the same spring while investigating how load affects extension?

1. To remove the need for measurements
2. To control the spring's properties
3. To change two independent variables at once
4. To make the load a dependent variable