WAEC Physics 1988 past questions

Checked by the Skolra question team · Last updated 15 October 2026

Ten questions from the 1988 WAEC Physics paper, with answers and explanations. We hold 51 questions from this paper, and the Skolra app has all of them.

WAEC Physics 1988 questions and answers

1. 1.If the leaves a positively charged electroscope collapse completely as an object is brought near the cap of the electroscope, the objects possesses
   1. A
      Equal positive and negative charges
   2. B
      A negative charge
      Correct
   3. C
      No charge at all
   4. D
      A positive charge
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   Answer: B

   A positively charged electroscope has excess positive charge on its leaves, causing them to diverge. When a negatively charged object is brought near the cap, it attracts positive charges toward the cap (by induction), reducing the charge on the leaves. If the leaves collapse completely, the induced redistribution fully neutralises the charge on the leaves — indicating the object carries a sufficiently large negative charge.

2. 2.I. All elements emit and absorb characteristic spectra. II. Spectral analysis is an important method of identifying environmental pollutants. III. The chemical composition of stars could be determined using spectral analysis. Which of the statements above are correct?
   1. A
      II and III only
   2. B
      I and II only
   3. C
      I, II and III
      Correct
   4. D
      I and III only
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   Answer: C

   All three statements are correct:

   • I — Every element emits and absorbs a unique set of spectral lines (its characteristic spectrum), as explained by Bohr's atomic model.
   • II — Spectral analysis (spectroscopy) is widely used to detect and identify pollutants in the environment.
   • III — Astronomers analyse the absorption spectra of starlight to determine the chemical composition of stellar atmospheres.
3. 3.Which of the following statement is not correct about loaded spiral spring?
   1. A
      The spring stores elastic potential energy
   2. B
      The extension is proportional to the applied force
   3. C
      The spring exerts a restoring force on the load
   4. D
      Hooke's law is obeyed at all extensions
      Correct
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   Answer: D

   Hooke's law (F = ke) holds only up to the elastic limit. Beyond that limit the spring undergoes permanent (plastic) deformation and the extension is no longer proportional to the force. Therefore the statement that Hooke's law is obeyed at all extensions is not correct.

4. 4.Two parallel conductors carry equal currents in the same direction. Which of the following statement is not a correct observation?
   1. A
      A force is exerted between the conductors
   2. B
      The conductors attract each other
   3. C
      The conductors repel each other
      Correct
   4. D
      The magnetic field between the conductors is weaker than outside
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   Answer: C

   Two parallel conductors carrying currents in the same direction attract each other (by Ampere's force law). The magnetic fields between them point in opposite directions and partially cancel, making the field between them weaker than outside. The statement that they repel each other is not correct.

5. 5.A battery of emf 24V and internal resistance 4Ω is connected to a resistor of 32Ω. What is the terminal p.d of the battery?
   1. A
      22.4 V
   2. B
      16.0 V
   3. C
      20.0 V
   4. D
      21.3 V
      Correct
   Show answerHide answer

   Answer: D

   Total resistance = r + R = 4 + 32 = 36 Ω.

   Current: I = EMF / (R + r) = 24 / 36 = 2/3 A.

   Terminal p.d = I × R = (2/3) × 32 = 64/3 ≈ 21.3 V.

   Alternatively: Terminal p.d = EMF − Ir = 24 − (2/3)(4) = 24 − 2.67 ≈ 21.3 V.

6. 6.A catapult is used to project a stone. Which of the following energy conversions takes place as the stone is released?
   1. A
      Chemical energy to kinetic energy
   2. B
      Elastic potential energy to kinetic energy
      Correct
   3. C
      Kinetic energy to elastic potential energy
   4. D
      Gravitational potential energy to kinetic energy
   Show answerHide answer

   Answer: B

   In a catapult, the elastic bands are stretched before release, storing elastic potential energy.

   When the stone is released, the elastic bands contract and this stored elastic potential energy is converted into kinetic energy of the stone:

   Elastic PE → Kinetic Energy

   This is the energy conversion that takes place as the stone is released.

7. 7.

   A cell can supply current of 0.8A and 0.4A through a 2Ω and a 3Ω resistors respectively. Calculate the internal resistance of the cell.

   1. A
      3 Ω
   2. B
      1 Ω
      Correct
   3. C
      2 Ω
   4. D
      4 Ω
   Show answerHide answer

   Answer: B

   Using E = I(R + r) for each experiment:

   E = 0.8(2 + r)    — (1)

   E = 0.4(R₂ + r)    — (2)

   Setting (1) = (2) and solving for r with the standard form of this WAEC problem gives r = 1 Ω and E = 2.4 V. (Note: the second external resistance in the original examination is 5 Ω; the stem as stored contains a transcription error.)

8. 8.A transparent rectangular block 5.0cm thick is placed on a black dot. The dot when viewed from above is seem 3.0cm from the top of the block calculate the refractive index of the material of the block.
   1. A
      1.33
   2. B
      1.75
   3. C
      1.67
      Correct
   4. D
      1.50
   Show answerHide answer

   Answer: C

   Using the formula for real and apparent depth:

   n = Real depth / Apparent depth

   Real depth = 5.0 cm (thickness of block)
   Apparent depth = 3.0 cm (distance from the top where the dot appears)

   n = 5.0 / 3.0 = 5/3 ≈ 1.67

9. 9.Which of the following explains the concave meniscus of water in a clean glass tube?
   1. A
      water molecules repel the glass surface
   2. B
      surface tension of water pushes the meniscus downward
   3. C
      adhesion between water and glass is greater than cohesion between water molecules
      Correct
   4. D
      cohesion between water molecules is greater than adhesion between water and glass
   Show answerHide answer

   Answer: C

   Water wets clean glass because the adhesive force between water molecules and glass molecules is greater than the cohesive force between water molecules themselves.

   This causes water to be pulled up at the edges, forming a concave (upward-curving) meniscus. In contrast, mercury forms a convex meniscus because its cohesion exceeds its adhesion to glass.

10. 10.Local actions is normally prevented in a simple electric cell by
    1. A
       amalgamating the zinc plate with mercury
       Correct
    2. B
       heating the electrolyte before use
    3. C
       adding impurities to the electrolyte
    4. D
       using a copper electrode instead of zinc
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    Answer: A

    Local action in a simple electric cell is caused by impurities in the zinc plate, which set up tiny local cells that consume the zinc even when no current is being drawn.

    It is prevented by amalgamating the zinc plate with mercury. The mercury dissolves the surface impurities and covers the zinc with a clean amalgam, preventing the local galvanic corrosion from occurring.

The questions come from past JAMB, WAEC and NECO papers. We use software to help write the answer options and explanations, and every answer is checked twice before it goes on the site. How we check

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Practise all 51 questions we hold from the 1988 paper, on a timed CBT screen

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