General Practical Physics II — 2025 Past Questions

University of Ilorin PHY108: 48 questions.

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

1. The relationship between the frequency and the length of a vibrating spring wire is described as a/an
   1. Direct relationship
   2. Diagonal relationship
   3. Inverse relationship
   4. Exponential relationship
2. Which of the following components is NOT used in a standard potentiometer circuit?
   1. Standard cell
   2. Uniform resistance wire
   3. Galvanometer
   4. Capacitor
3. How many lenses are needed in a simple microscope experiment?
   1. One lens
   2. Two lenses
   3. Multiple lenses
   4. No lens
4. What is the relationship between EMF (E) and terminal voltage (V) when current flows through a cell with internal resistance?
   1. E > V
   2. E < V
   3. E = V
   4. E and V are unrelated
5. In measurement science, 'error' is also referred to as:
   1. Mistake
   2. Uncertainty
   3. Deviation
   4. Blunder
6. Why does a potentiometer have a uniform scale (uniform resistance wire)?
   1. To ensure equal current distribution at all points
   2. To maintain a uniform potential gradient along the wire so voltage is proportional to length
   3. To reduce the internal resistance of the circuit
   4. To prevent overheating of the resistance wire
7. What is the function of the standard cell in a potentiometer setup?
   1. To provide the driving current for the potentiometer wire
   2. To serve as the reference EMF against which unknown EMFs are compared
   3. To detect the balance point using galvanometer deflection
   4. To increase the resistance of the potentiometer circuit
8. The EMF of a standard cell is 1.018 V. The balance point of the standard cell is at 50 cm and that of the test cell is at 55 cm. What is the EMF of the test cell?
   1. 1.12 V
   2. 1.02 V
   3. 0.925 V
   4. 1.18 V
9. In a potentiometer experiment, which component is the jockey (sliding contact) connected to?
   1. Potentiometer wire
   2. Galvanometer
   3. Daniel cell
   4. Standard cell
10. In an electrical circuit, what is the relationship between potential difference (V) and current (I) across a resistor?
    1. V is directly proportional to I (V ∝ I)
    2. V is inversely proportional to I
    3. V is proportional to I²
    4. V is independent of I
11. An object is placed 8 cm from a concave lens of focal length 12 cm. What is the image distance?
    1. +4.8 cm
    2. −4.8 cm
    3. +24 cm
    4. −24 cm
12. In an electricity experiment, no current is flowing in the circuit. What will be the value of the potential difference (pd)?
    1. Indeterminate
    2. Half the EMF
    3. Equal to the EMF
    4. Zero
13. If an object is placed at the focus of a convex lens, where will the image form?
    1. At the centre of curvature
    2. At infinity
    3. At the focus on the other side
    4. Between the focus and the lens
14. If an object is placed between the focus (F) and the centre of curvature (2F) of a convex lens, what is the nature of the image?
    1. Magnified, real, and inverted
    2. Virtual and erect
    3. Diminished, real, and inverted
    4. Magnified and virtual
15. In a convex lens–liquid experiment, the distance from pin to lens is 14.8 cm and from pin to mirror is 15.2 cm. What is the focal length of the lens?
    1. 24 cm
    2. 18 cm
    3. 15 cm
    4. 20 cm
16. When a cell is connected to an external resistance R, why is the terminal pd less than the EMF?
    1. External resistance consumes all the voltage
    2. Internal resistance of the cell causes a voltage drop
    3. Current in the circuit reduces EMF
    4. Voltage drops across connecting wires
17. What is the function of the jockey in a potentiometer experiment?
    1. It drives current through the potentiometer wire
    2. It acts as a sliding contact to tap off variable potential difference along the wire
    3. It measures the EMF of the standard cell directly
    4. It acts as a switch to disconnect the galvanometer
18. Which of the following is an example of a systematic error?
    1. Misreading a scale due to inattention
    2. Zero error in a measuring instrument
    3. Random fluctuations in repeated readings
    4. Recording the wrong value by mistake
19. Which of the following correctly expresses the formula for electrical power (P) in terms of EMF (E), internal resistance (r), and external resistance (R)?
    1. P = E²/(R + r)
    2. P = E²R/(R + r)²
    3. P = E/(R + r)
    4. P = E²r/(R + r)²
20. What is the SI unit of viscosity?
    1. Pascal (Pa)
    2. Pascal-second (Pa·s)
    3. Newton per metre (N/m)
    4. Kilogram per metre (kg/m)
21. How many lenses does a simple microscope have, and how many does a compound microscope have?
    1. Simple: 1 lens; Compound: 2 lens systems (objective and eyepiece)
    2. Simple: 2 lenses; Compound: 3 lenses
    3. Simple: 1 lens; Compound: 1 lens
    4. Simple: 3 lenses; Compound: 2 lenses
22. What is used to check if the legs of a spherometer are touching the lens surface?
    1. Paper
    2. Mica
    3. Water
    4. Air
23. In the convex lens–liquid experiment, the focal length of the lens–liquid combination is given by:
    1. The sum of the no-parallax distances from the lens and the mirror
    2. The mean (average) of the no-parallax distances from the lens and the mirror
    3. The difference between the distances
    4. The product of the two distances
24. What is the nature of the final image formed by a compound microscope?
    1. Real and erect
    2. Virtual and erect
    3. Virtual and inverted
    4. Real and inverted
25. What is the nature of the image formed by a simple microscope?
    1. Real, inverted, and magnified
    2. Virtual, erect, and magnified
    3. Real, erect, and diminished
    4. Virtual, inverted, and diminished
26. In a sonometer (vibrating string) experiment, what is the correct relationship between the length (L) of the string and the tension (T)?
    1. Inverse of length (1/L) against tension (T)
    2. Square of length (L²) against tension (T)
    3. Square root of length (√L) against tension (T)
    4. Length (L) against tension (T)
27. In a graph of 1/u plotted against 1/v (for a convex lens experiment), what does the intercept on either axis represent?
    1. f (focal length)
    2. 1/f (reciprocal of focal length)
    3. v (image distance)
    4. u (object distance)
28. Which of the following correctly expresses the internal resistance (r) of a cell in terms of EMF (E), terminal voltage (V), and external resistance (R)?
    1. r = E/V
    2. r = R(E − V)/V
    3. r = R(EV)/V
    4. r = V(E − R)/E
29. A resistor is connected in series with a cell of EMF (E) and internal resistance (r). What is the potential difference (pd) across the internal resistance?
    1. E − V, where V is terminal pd
    2. V (terminal pd itself)
    3. E (the full EMF)
    4. Zero, as internal resistance has no pd
30. In a series circuit, what is the pd across the fixed external resistor R?
    1. Equal to EMF (E)
    2. Equal to terminal pd (V = IR)
    3. Equal to the pd across internal resistance
    4. Zero when current flows
31. What type of images do the objective lens and eyepiece lens of a compound microscope form separately?
    1. Objective: real and inverted; Eyepiece: virtual and erect
    2. Objective: virtual and erect; Eyepiece: real and inverted
    3. Objective: real and erect; Eyepiece: virtual and inverted
    4. Both form virtual and erect images
32. What happens to the terminal potential difference (pd) when the external resistance in a circuit is increased?
    1. Terminal pd decreases
    2. Terminal pd increases
    3. Terminal pd remains constant
    4. Terminal pd becomes equal to zero
33. What is the formula for internal resistance (r) in a potentiometer experiment?
    1. r = R(V − E)/V
    2. r = R(E − V)/V
    3. r = E/V × R
    4. r = V/(E − V) × R
34. What is the final image produced by a compound microscope?
    1. Real and erect
    2. Real and inverted
    3. Virtual and inverted
    4. Virtual and erect
35. What does a spherometer measure?
    1. Focal length of a lens
    2. Radius of curvature of a lens or mirror surface
    3. Refractive index of a lens material
    4. Thickness of a glass slab
36. If 1/u is plotted against 1/v in a convex lens experiment, what does the slope of the graph give?
    1. Focal length (f)
    2. Reciprocal of focal length (1/f)
    3. Negative one (−1)
    4. Zero
37. Between the eyepiece and the objective lens of a compound microscope, which one has a shorter focal length?
    1. The eyepiece lens
    2. The objective lens
    3. Both have equal focal lengths
    4. The focal length depends on magnification only
38. For maximum magnification in a simple microscope, where should the object be placed?
    1. At the centre of curvature (2F)
    2. At the principal focus (F)
    3. Between the principal focus (F) and the lens
    4. Beyond the centre of curvature (beyond 2F)
39. Which of the following is NOT a characteristic of the image formed by a concave (diverging) lens?
    1. Real
    2. Virtual
    3. Diminished
    4. Erect
40. In the experiment for finding the refractive index of a convex lens material and an unknown liquid, how are the refractive index and focal length calculated?
    1. Using the lensmaker's equation and Snell's law applied to measured focal lengths of the lens alone and the lens-liquid combination
    2. By measuring the angle of refraction only
    3. By counting the number of images formed
    4. By measuring the thickness of the lens only
41. In a compound microscope, which lens has the shorter focal length?
    1. The eyepiece lens
    2. The objective lens
    3. Both lenses have equal focal lengths
    4. The condenser lens
42. What are the characteristics of the image formed by the objective lens of a compound microscope?
    1. Virtual, erect, and magnified
    2. Real, inverted, and magnified
    3. Virtual, inverted, and diminished
    4. Real, erect, and diminished
43. In a potentiometer experiment, the balance lengths for two cells are 50 cm and 75 cm. What is the ratio of their EMFs?
    1. 2:3
    2. 3:2
    3. 2:5
    4. 5:2
44. In a potentiometer experiment, if the balance length is 60 cm, what EMF does this length correspond to?
    1. E ∝ 60 cm (i.e., EMF is proportional to the 60 cm length)
    2. EMF = 60 V
    3. EMF = 0.60 V
    4. EMF cannot be determined from length alone without the potential gradient
45. If the balance length in a potentiometer decreases, what could be the reason?
    1. The EMF of the test cell was decreased
    2. The EMF of the test cell was increased
    3. The driving battery voltage was increased
    4. The resistance of the potentiometer wire increased
46. What causes no deflection in the galvanometer during a potentiometer experiment?
    1. When the driving battery is disconnected
    2. When the potential difference tapped from the wire equals the EMF of the test cell (null/balance point)
    3. When the jockey is at the midpoint of the wire
    4. When the galvanometer resistance is very high
47. In the experiment for finding the focal length of a convex lens using a concave lens, why is the convex lens necessary?
    1. The concave lens alone cannot form a real image that can be used as a virtual object for further measurement
    2. The convex lens measures the refractive index of the concave lens
    3. The convex lens replaces the plane mirror in the experiment
    4. The convex lens reduces spherical aberration in the setup
48. Between the eyepiece and objective lens of a compound microscope, which one has the shorter focal length?
    1. Eyepiece lens
    2. Objective lens
    3. Both have the same focal length
    4. It depends on the magnification setting

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