General Practical Physics II — 2023 Past Questions

University of Ilorin PHY108: 101 questions.

Topics: Emphasis on quantitative measurements, error treatment, and graphical analysis, Experiments: light, Experiments: electrical and mechanical resonant systems, Experiments: mechanical systems

1. What is the relationship between the frequency and the length of a vibrating wire?
   1. Direct relationship
   2. Diagonal relationship
   3. Inverse relationship
   4. No relationship
2. A graph of (E−V)⁻¹ was plotted against I⁻¹, which gave a constant of 4.24 AV⁻¹. What is the value of the internal resistance?
   1. 4.24 Ω
   2. 0.24 Ω
   3. 0.22 Ω
   4. 2.40 Ω
3. A graph of the ratio of image size to object size (magnification) was plotted against the image distance (v). Which of the following is true?
   1. The focal length is equal to the gradient of the graph
   2. The focal length is equal to the inverse of the gradient
   3. The focal length is directly proportional to the gradient
   4. The focal length equals the y-intercept of the graph
4. An experiment was conducted using a liquid, lens, metre rule, vernier caliper, and retort stand. Which of the following is to be determined?
   1. Refractive index of the lens only
   2. Refractive indices of both the lens and liquid
   3. Focal length of the lens only
   4. Focal length of both the liquid and the lens
5. The focal length of a lens is defined as:
   1. The distance from centre of curvature to radius of lens
   2. The distance from optical centre to the principal axis
   3. The distance from the optical centre to the principal focus
   4. The distance from the principal focus to the centre of curvature
6. Which of the following errors must be avoided to ensure accuracy in a simple microscope experiment?
   1. Random error
   2. Erratic error
   3. Systematic error
   4. Parallax error
7. The focus of a concave mirror is the point where rays of light:
   1. Diverge before reflection
   2. Converge before reflection
   3. Diverge after reflection
   4. Converge after reflection
8. The refractive index of a material is the ratio of:
   1. Speed of light in air to speed of light in vacuum
   2. Speed of light in water to speed of light in the material
   3. Speed of light in the material to speed of light in water
   4. Speed of light in vacuum to speed of light in the material
9. The standard EMF of a Weston standard cell (battery reference) is:
   1. 4.5 V
   2. 1.51 V
   3. 0.3 V
   4. 1.018 V
10. The scale of a travelling microscope is similar to the scale of:
    1. Metre rule
    2. Vernier caliper
    3. Tape rule
    4. Micrometer screw gauge
11. Opening the switch of a circuit when taking a reading helps to:
    1. Make the reading constant
    2. Prevent short circuiting
    3. Help the circuit not to be destroyed
    4. Prevent battery discharge
12. If current was passed through a circuit of voltage 2 V and resistance 10 Ω for 20.0 s, calculate the charge in the circuit.
    1. 40 C
    2. 4 C
    3. 0.4 C
    4. 400 C
13. An object is placed 20 cm from a convex lens and gives an image 80 cm from the lens. Calculate the focal length of the lens.
    1. 16 cm
    2. 20 cm
    3. 25 cm
    4. 10 cm
14. An object is placed 10 cm from a convex lens of focal length 15 cm. Calculate the magnification of the lens.
    1. 3
    2. 0.33
    3. −3
    4. 1.5
15. When an object of height 5 cm is placed 12 cm away from a converging lens of focal length 8 cm, what is the size (height) of the image?
    1. 24 cm
    2. 10 cm
    3. 5 cm
    4. 15 cm
16. A student uses 2.97 × 10⁸ m/s instead of 3.0 × 10⁸ m/s for the speed of light. What is the percentage error?
    1. 1%
    2. 3%
    3. 0.1%
    4. 10%
17. In a potentiometer experiment, R₁ = x with balance length L₁ = 40 cm, and R₂ = 3 Ω with balance length L₂ = 60 cm. Calculate R₁.
    1. 2 Ω
    2. 4 Ω
    3. 1.5 Ω
    4. 6 Ω
18. When a graph of uv (product of object and image distances) is plotted against (u+v) (sum of object and image distances), what is the slope?
    1. 0
    2. Infinity
    3. f (focal length)
    4. 1/f (inverse of focal length)
19. The images formed by a convex lens are always:
    1. Real and inverted (when object is beyond F)
    2. Virtual and erect always
    3. Diminished always
    4. Erect and real always
20. In the lensmaker's equation, what do the two points (R₁ and R₂) represent?
    1. Conjugate foci
    2. Focal points
    3. Centres of curvature of the two lens surfaces
    4. Optical centres
21. A ray of light passes from air into water with an incidence angle of 20°. What is the refracted angle? (Refractive index of water = 4/3)
    1. 26.8°
    2. 14.86°
    3. 41.8°
    4. 20°
22. What is the use of a spherometer?
    1. To measure the diameter of a lens
    2. To measure the thickness of a glass plate only
    3. To measure the radius of curvature of a curved surface (lens or mirror)
    4. To measure the focal length of a lens directly
23. What is the correct precaution in the use of a spherometer?
    1. Avoid random error only
    2. Always use on a flat surface only
    3. Avoid erratic error
    4. Ensure three-leg balance on the surface and check for zero error
24. The prism can be used for which of the following?
    1. Dispersion of light into its component colours
    2. Reflection of light only
    3. To arrange, reflect, and transmit light into its colours
    4. Transmission of light into its colours only
25. A graph of V was plotted against I from the standard equation V = E − Ir. If the slope is 0.1 and the intercept is 3, calculate the internal resistance of the cell.
    1. 0.1 Ω
    2. 10 Ω
    3. 3 Ω
    4. 0.3 Ω
26. A graph of V was plotted against I from the standard equation V = E − Ir. If the slope is 0.1 and the y-intercept is 3, calculate the EMF of the cell.
    1. 3 V
    2. 0.3 V
    3. 0.1 V
    4. 30 V
27. A converging lens with a focal length of 10 cm forms an image when an object is placed 30 cm away. Calculate the image distance.
    1. 15 cm
    2. 30 cm
    3. 10 cm
    4. 20 cm
28. A diverging lens forms an image at 3 cm when an object is placed at 2 cm. Calculate the power of the lens in dioptres.
    1. 0.833 D
    2. 8.33 D
    3. 83.3 D
    4. 0.083 D
29. A graph of the ratio of image size to object size (magnification, m) is plotted against the image size (v). Which is true about the slope of the graph?
    1. The slope is the focal length of the lens
    2. The slope is equal to zero
    3. The focal length is the inverse of the slope of the graph
    4. The slope equals the object distance
30. When the graph of the sum of image and object distances (u+v) is plotted against their product (uv), what does the slope of the graph represent?
    1. The inverse of the focal length (1/f)
    2. The focal length (f)
    3. The linear magnification
    4. The object distance (u)
31. When an object is placed between the focal point (F) and the optical centre of a convex lens, the image formed is:
    1. Erect and diminished
    2. Erect and magnified
    3. Inverted and magnified
    4. Inverted and diminished
32. When a graph of y = X is plotted, which of the following is true?
    1. The graph is a straight line with y-intercept of 4
    2. The graph is a straight line with X-intercept of 4
    3. The graph is a straight line parallel to X-axis
    4. The graph is a straight line with zero intercept
33. An ammeter and voltmeter are connected across a load in a circuit. Which connection is correct?
    1. Ammeter in series and voltmeter in parallel across the load
    2. Ammeter in parallel and voltmeter in series across the load
    3. Both ammeter and voltmeter in parallel across the load
    4. Both ammeter and voltmeter in series across the load
34. A lens that has a thinner centre and a thicker edge is known as:
    1. Converging lens
    2. Diverging lens
    3. Plano-convex lens
    4. Biconvex lens
35. Which kind of wave is produced in a sonometer experiment?
    1. Mechanical waves (stationary/standing waves)
    2. Electromagnetic waves
    3. Transverse progressive waves
    4. Longitudinal waves only
36. The vernier microscope (travelling microscope) can be used to measure critical angle using which method?
    1. Total internal reflection method
    2. Fish-eye method
    3. None of the above
    4. Refraction method
37. How many legs does a spherometer have?
    1. 4
    2. 3
    3. 5
    4. 2
38. The velocity of light through glass is 1.98 × 10⁸ m/s. Find the refractive index of glass.
    1. 1.52
    2. 1.98
    3. 1.33
    4. 2.00
39. The critical angle when a ray of light passes from air to water is 58.7°. Find the refractive index of glass. (Refractive index of water = 1.33)
    1. 1.43
    2. 1.92
    3. 1.17
    4. 1.60
40. Which of the following is true concerning a compound microscope?
    1. The objective lens has a larger focal length than the eyepiece
    2. The eyepiece has a larger focal length than the objective lens
    3. Both the eyepiece and objective lens have the same focal length
    4. The objective lens has no focal length
41. The image formed by a convex mirror is:
    1. Inverted, real, and diminished
    2. Erect, virtual, and diminished
    3. Erect, real, and diminished
    4. Inverted, virtual, and diminished
42. The speed of light in a medium is 1.91 × 10⁸ m/s. Find its refractive index.
    1. 2.4
    2. 1.9
    3. 1.57
    4. 2.33
43. The accuracy of a potentiometer depends on?
    1. Length of wire
    2. Mode of connection
    3. Temperature
    4. Range and sensitivity of the galvanometer
44. A diagram was given. The real depth is R₃−R₁ and the apparent depth is R₃−R₂. Given R₃ = 7.5, R₂ = 5.5, and R₁ = 4.5. Calculate the refractive index.
    1. 1.5
    2. 2.0
    3. 3.0
    4. 1.33
45. Calculate the tension in a sonometer wire. Given: mass = 80 g, length L = 70 cm, frequency f = 20 Hz.
    1. 89.6 N
    2. 8.96 N
    3. 0.896 N
    4. 896 N
46. When is EMF equal to the potential difference of a cell?
    1. When the internal resistance is zero
    2. When the external resistance is maximum
    3. When current is maximum
    4. When the cell is fully charged
47. What is the definition of parallax?
    1. The apparent relative movement of two objects due to a movement on the part of the observer
    2. The difference between real position and apparent position of an object
    3. The movement of two objects at the same time
    4. The error caused by incorrect calibration of instruments
48. A ray of light passes from air into water with an incidence angle of 30°. Find the angle of refraction. (Refractive index of water = 4/3)
    1. 22.1°
    2. 14.86°
    3. 41.8°
    4. 30°
49. In a standard measurement circuit, the ammeter and voltmeter are connected as:
    1. Ammeter in series, voltmeter in parallel
    2. Ammeter in series, voltmeter in series
    3. Ammeter in parallel, voltmeter in parallel
    4. Ammeter in parallel, voltmeter in series
50. Which of the following errors is avoided to ensure accuracy during a microscope experiment?
    1. Systematic error
    2. Random error
    3. Erratic error
    4. Parallax error
51. Which of the following is NOT true of both the simple and compound microscope?
    1. Image is erect
    2. Image is diminished
    3. Image is magnified
    4. Image is virtual
52. The objective lens and eyepiece of a microscope are both:
    1. Convex lenses with the same focal length
    2. Convex lenses with different focal lengths
    3. Concave lenses with different focal lengths
    4. One convex and one concave lens
53. Calculate the refractive index if the speed of light in glass is 1.9 × 10⁸ m/s.
    1. 1.58
    2. 1.90
    3. 1.33
    4. 2.00
54. What is the relationship between the frequency of vibration and the length of a vibrating string?
    1. Directly proportional
    2. Inversely proportional
    3. None of the above
    4. Proportional to the square of length
55. What is used to check the balance position of the legs of a spherometer?
    1. Pin
    2. Thread
    3. Thin paper
    4. Water
56. A student was given a lens, metre rule, plumb line, spherometer, and pins. What is the aim of the experiment?
    1. To determine the focal length of the lens
    2. To determine the refractive index of the lens and the liquid
    3. To determine the refractive index of the lens only
    4. To determine the focal length of the lens and liquid
57. When a graph of magnification (m) produced by a convex lens is plotted against image distance (v), what does the slope of the graph represent?
    1. The inverse of the focal length (1/f)
    2. The focal length (f)
    3. The object distance (u)
    4. The inverse of the object distance (1/u)
58. An object 5.0 cm high is placed 12.0 cm in front of a convex lens of focal length 8.0 cm. What is the size of the image?
    1. 10.0 cm
    2. 23.0 cm
    3. 41.0 cm
    4. 2.5 cm
59. What does a convex lens do to light rays?
    1. Converge rays at a point (principal focus)
    2. Spread out (diverge) rays
    3. Neither converge nor diverge rays
    4. Reflect rays back
60. Which of the following is NOT a characteristic of a concave (diverging) lens?
    1. Real image
    2. Virtual image
    3. Diminished image
    4. Erect image
61. When the magnification of a lens is less than one, the image formed is:
    1. Inverted
    2. Real
    3. Diminished
    4. All of the above
62. All these are types of errors EXCEPT:
    1. Systematic error
    2. Random error
    3. Erratic error
    4. Rule error
63. The frequency f of a wire at resonance, equal to the frequency of the tuning fork, is given by the relation:
    1. f = (1/2L)√(T/μ)
    2. f = (1/2)√(T/μ)
    3. f = (1/2L)√(μ/T)
    4. f = (1/2)√(μ/T)
64. The thickness of the central portion of a thin converging lens can be determined very accurately using?
    1. Vernier caliper
    2. Micrometer screw gauge
    3. Telescope
    4. Microscope
65. The inner diameter of a small test tube can be measured accurately using?
    1. Micrometer screw gauge
    2. Pair of dividers
    3. Metre rule
    4. Pair of Vernier calipers
66. What is the least possible error in using a rule graduated in centimetres?
    1. 0.1 cm
    2. 0.5 cm
    3. 1.0 cm
    4. 2.0 cm
67. Which of the following has a reading accuracy of 0.5 mm?
    1. Vernier calipers
    2. Micrometer screw gauge
    3. Metre rule
    4. Protractor
68. What is the reading of the vernier scale shown, where the main scale reads between 1.8 cm and 1.9 cm, and the 8th vernier division coincides?
    1. 1.88 cm
    2. 1.80 cm
    3. 1.28 cm
    4. 1.97 cm
69. Given that MgT² = 4Mπ²L + gk², the plot of T² against L gives a straight line with:
    1. Slope = 4π²m, intercept = gk²
    2. Slope = 4π²/g, intercept = gk²/m
    3. Slope = 4π²/g, intercept = k²/m
    4. Slope = k², intercept = 4π²
70. An object is placed 10 cm in front of a concave mirror of focal length 15 cm. What is the position and nature of the image formed?
    1. 30 cm in front of the mirror, virtual and erect
    2. 60 cm in front of the mirror, real and inverted
    3. 60 cm behind the mirror, virtual and erect
    4. 30 cm behind the mirror, real and inverted
71. An object is placed 30 cm from a concave mirror of focal length 15 cm. Calculate the linear magnification.
    1. 0
    2. 2/3
    3. 1
    4. 2
72. In a graph of 1/v against 1/u, the gradient (slope) of the graph is:
    1. 1 (positive one)
    2. −1 (negative one)
    3. 1/f
    4. f
73. The magnifying power of a simple microscope is:
    1. v/u
    2. −(D + 1)/f
    3. (D/f − 1)
    4. 1/v + 1/u
74. The magnifying power of a compound microscope is:
    1. −(D/f + 1)(v/f − 1)
    2. (D/f − 1)(v/f − 1)
    3. D/f − 1
    4. fo/fe
75. The magnifying power of an astronomical telescope is:
    1. f_o/f_e
    2. f_e/f_o
    3. −(D/f + 1)
    4. f_o + f_e
76. The power of a lens is:
    1. u/v + u/v
    2. v/u
    3. 1/f
    4. None of these
77. The lensmaker's equation is:
    1. 1/v + 1/u = 1/f
    2. M = v/f − 1
    3. 1/f = (n₂−n₁)/n₁ × (1/R₁ + 1/R₂)
    4. None of these
78. The resistance of an open series circuit is:
    1. Zero
    2. One
    3. Infinity
    4. Half
79. Which of the following obeys Ohm's Law?
    1. Glass
    2. Diode
    3. All electrolytes
    4. All metals
80. A calibrated potentiometer is used to measure the EMF of a cell because:
    1. The potentiometer has a linear scale
    2. The potentiometer takes no current from the cell being measured
    3. The resistance of the potentiometer is less than that of a voltmeter
    4. The internal resistance of the cell is small
81. The resistance of a voltmeter is usually very:
    1. High
    2. Low
    3. Dependable
    4. Risky
82. The ratio between the voltage drop across a conductor and the current through it is known as:
    1. EMF
    2. Resistance
    3. Voltage divider
    4. None of these
83. Which of the following is NOT an ohmic conductor?
    1. Copper wire
    2. Constantan wire
    3. Manganin wire
    4. Filament lamp
84. The resistance of an ammeter is usually very:
    1. High
    2. Low
    3. Dependable
    4. Risky
85. Which of the following is NOT a part of a DC electric motor?
    1. Field magnet
    2. Armature
    3. Commutator
    4. Transformer
86. To convert a galvanometer into an ammeter, which of the following is required?
    1. A high resistance in parallel
    2. A high resistance in series
    3. A low resistance in parallel
    4. A low resistance in series
87. To convert a galvanometer into a voltmeter, which of the following is required?
    1. A low series resistance
    2. A low parallel resistance
    3. A high series resistance
    4. A high parallel resistance
88. When the object distance 'u' is less than the focal length of a convex lens, the image formed is:
    1. Real, inverted, and magnified
    2. Virtual, erect, and magnified
    3. Real, erect, and diminished
    4. Virtual, inverted, and enlarged
89. In the determination of focal length of a convex lens by the simple method, the following apparatus were required:
    1. Converging lens, metre rule, and screen
    2. Diverging lens, vernier calipers, and screen
    3. Converging lens, paper, and screen
    4. Diverging lens, vernier caliper, and screen
90. A graph of (u+v) versus uv was plotted using both sets of data. The slope of the graph is:
    1. f (focal length)
    2. 1/f (inverse of focal length)
    3. v/f
    4. f₁ + f₂
91. In a graph of magnification (m) versus image distance (v), the slope and vertical intercept of the graph are:
    1. f and 1
    2. 1/f and 1
    3. 1/f and −1
    4. −1 and 1/f
92. The diagram represents a micrometer screw gauge with the horizontal scale showing between 3 and 4 mm, and the thimble scale showing 22. What is the reading?
    1. 3.72 mm
    2. 3.50 mm
    3. 3.30 mm
    4. 3.22 mm
93. The expression for the 'lost voltage' (voltage lost internally) of a cell in terms of EMF (E) and internal resistance (r) is:
    1. V = E + Ir
    2. E − V = Ir
    3. V = Ir − E
    4. E + V = Ir
94. Which of the following instruments has a reading accuracy of 0.01 mm?
    1. Vernier calipers
    2. Micrometer screw gauge
    3. Metre rule
    4. Travelling microscope
95. In a graph of (L² − D²) versus L for the displacement method of finding focal length, the slope of the graph is:
    1. F (focal length)
    2. 4/F
    3. 4F
    4. F − 4
96. Two physics groups measured acceleration due to gravity as 971 ± 10 cm/s² and 988 ± 11 cm/s² respectively. Do the two readings agree within their experimental error?
    1. No
    2. Yes
    3. Not comparable
    4. None of the above
97. The associated error for every measurement is affected by which of the following?
    1. Choice of instrument, condition and calibration, skill of user only
    2. Choice of instrument, condition and calibration, skill and care of user
    3. Choice of instrument, condition and calibration, skill and care of user, and nature of measurement process
    4. Nature of the process of measurement only
98. The closeness with which a series of measurements agree with one another, independently of any systematic error, is defined as:
    1. Accuracy
    2. Actual value
    3. Precision
    4. Absolute value
99. The error in the slope of a graph can be calculated using the relationship:
    1. 4wn/R
    2. 4w/(nR)
    3. 4R/wn
    4. √(4w)/(nR)
100. Which of the following instruments would you use to measure both the internal and external diameter of a hollow pipe?
     1. Micrometer screw gauge
     2. A millimetre
     3. A metre rule
     4. Vernier caliper

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