WAEC Physics Past Questions and Answers (Fully Solved)

Below are 20 WAEC-style Physics questions with full solutions and explanations.

1. WAEC Physics Question (Mechanics – Speed, Distance, Time)

A car travels a distance of 180 km in 3 hours. It then continues for another 120 km in 2 hours. Calculate:

• (a) The average speed for the whole journey.
• (b) The total time taken in seconds.

Solution:

Total distance = 180 km + 120 km = 300 km.

Total time = 3 h + 2 h = 5 h.

Average speed, v = Total distance / Total time = 300 km / 5 h = 60 km h^-1.

Convert hours to seconds:

5 h = 5 × 60 × 60 = 18 000 s.

Answer: (a) 60 km h^-1 (b) 18 000 s.

2. WAEC Physics Question (Mechanics – Acceleration)

A body initially at rest is uniformly accelerated to a speed of 20 m s^-1 in 10 s. Find:

• (a) Its acceleration.
• (b) The distance moved in this time.

Solution: Initial velocity, u = 0; final velocity, v = 20 m s^-1; time, t = 10 s.

(a) Acceleration, a = (v – u)/t = (20 – 0)/10 = 2 m s^-2.

(b) Distance, s = ut + 1/2 at² = 0 × 10 + 1/2 × 2 × 10² = 1 × 100 = 100 m.

Answer: (a) 2 m s^-2 (b) 100 m.

3. WAEC Physics Question (Mechanics – Newton's Second Law)

A resultant force of 15 N acts on a body of mass 3 kg. Calculate the acceleration produced and the velocity after 4 s if the body starts from rest.

Solution: From Newton's second law, F = ma.

Given F = 15 N, m = 3 kg.

a = F/m = 15 / 3 = 5 m s^-2.

Initial velocity, u = 0 (from rest). Velocity after 4 s:

v = u + at = 0 + 5 × 4 = 20 m s^-1.

Answer: Acceleration = 5 m s^-2; velocity after 4 s = 20 m s^-1.

4. WAEC Physics Question (Mechanics – Work and Energy)

A force of 50 N pulls a box along a horizontal floor through a distance of 8 m. Calculate the work done. If this is done in 20 s, find the power developed.

Solution: Work done, W = F × d = 50 N × 8 m = 400 J.

Power, P = Work done / time = 400 J / 20 s = 20 W.

Answer: Work done = 400 J; power = 20 W.

5. WAEC Physics Question (Mechanics – Potential Energy)

A stone of mass 0.5 kg is raised to a height of 6 m above the ground. Take g = 10 m s^-2. Calculate its potential energy at this height.

Solution: Potential energy, PE = mgh.

m = 0.5 kg, g = 10 m s^-2, h = 6 m.

PE = 0.5 × 10 × 6 = 5 × 6 = 30 J.

Answer: 30 J.

6. WAEC Physics Question (Mechanics – Density)

A metal block has a mass of 600 g and a volume of 200 cm³. Find its density in kg m^-3.

Solution: Density, ρ = mass / volume.

First convert to SI units: mass = 600 g = 0.6 kg; volume = 200 cm³.

1 m³ = 10⁶ cm³ so 200 cm³ = 200 × 10^-6 m³ = 2.0 × 10^-4 m³.

ρ = 0.6 / (2.0 × 10^-4) = 0.6 ÷ 0.0002 = 3000 kg m^-3.

Answer: 3.0 × 10³ kg m^-3.

7. WAEC Physics Question (Waves – Frequency and Period)

A sound wave has a frequency of 250 Hz. Calculate its period.

Solution: Period, T = 1/f.

f = 250 Hz, so T = 1/250 = 0.004 s (or 4.0 × 10^-3 s).

Answer: 4.0 × 10^-3 s.

8. WAEC Physics Question (Waves – Wave Speed)

A water wave has a wavelength of 0.5 m and a frequency of 4 Hz. Find the speed of the wave.

Solution: Wave speed, v = fλ.

v = 4 Hz × 0.5 m = 2 m s^-1.

Answer: 2 m s^-1.

9. WAEC Physics Question (Sound – Echo)

A man stands 85 m from a high wall and claps his hands. He hears the echo 0.5 s later. Calculate the speed of sound in air from this experiment.

Solution: The sound travels from man to wall and back, so distance covered = 2 × 85 m = 170 m.

Time taken = 0.5 s.

Speed, v = distance / time = 170 / 0.5 = 340 m s^-1.

Answer: 340 m s^-1.

10. WAEC Physics Question (Light – Refraction)

The refractive index of glass is 1.5. Calculate the speed of light in the glass. (Take speed of light in vacuum, c = 3.0 × 10⁸ m s^-1.)

Solution: Refractive index, n = c / v, where v is speed in the medium.

v = c / n = (3.0 × 10⁸) / 1.5 = 2.0 × 10⁸ m s^-1.

Answer: 2.0 × 10⁸ m s^-1.

11. WAEC Physics Question (Light – Lenses)

An object is placed 30 cm in front of a converging lens of focal length 15 cm. Calculate the image distance.

Solution: Lens formula: 1/f = 1/v + 1/u.

Here, f = +15 cm (converging), u = -30 cm (object distance is taken negative by sign convention).

1/15 = 1/v + 1/(-30) = 1/v – 1/30.

Bring 1/30 to LHS:

1/15 + 1/30 = 1/v.

LCM is 30: 1/15 = 2/30, so 2/30 + 1/30 = 3/30 = 1/10.

So 1/v = 1/10, hence v = 10 cm (positive, real image).

Answer: 10 cm in front of the lens (on the opposite side of the object).

12. WAEC Physics Question (Electricity – Ohm's Law)

A resistor has a resistance of 6 Ω. When a potential difference of 12 V is applied across it, calculate the current flowing and the power dissipated.

Solution: From Ohm's law, V = IR.

I = V/R = 12 / 6 = 2 A.

Power, P = VI = 12 × 2 = 24 W.

Answer: Current = 2 A; power = 24 W.

13. WAEC Physics Question (Electricity – Series Resistors)

Three resistors of 2 Ω, 4 Ω and 6 Ω are connected in series across a 24 V battery. Find:

• (a) The total resistance.
• (b) The current in the circuit.

Solution: For series connection, R_total = R₁ + R₂ + R₃.

R_total = 2 + 4 + 6 = 12 Ω.

Current, I = V / R_total = 24 / 12 = 2 A.

Answer: Total resistance = 12 Ω; current = 2 A.

14. WAEC Physics Question (Electricity – Parallel Resistors)

Two resistors of 3 Ω and 6 Ω are connected in parallel across a 12 V source. Calculate the effective resistance and the total current drawn.

Solution: For parallel connection: 1/R_eq = 1/R₁ + 1/R₂.

1/R_eq = 1/3 + 1/6 = 2/6 + 1/6 = 3/6 = 1/2.

So R_eq = 2 Ω.

Total current, I = V / R_eq = 12 / 2 = 6 A.

Answer: Effective resistance = 2 Ω; total current = 6 A.

15. WAEC Physics Question (Electricity – Electrical Energy)

An electric iron rated 1000 W is used for 2 hours each day. Calculate the energy consumed in kWh and in joules.

Solution: Power, P = 1000 W = 1 kW, time t = 2 h.

Energy in kWh = Power (kW) × time (h) = 1 × 2 = 2 kWh.

1 kWh = 3.6 × 10⁶ J, so 2 kWh = 2 × 3.6 × 10⁶ = 7.2 × 10⁶ J.

Answer: 2 kWh or 7.2 × 10⁶ J.

16. WAEC Physics Question (Magnetism – Electromagnet)

State two ways of increasing the strength of an electromagnet used in a simple electric bell.

Solution / Answer:

• Increase the number of turns of the coil around the iron core.
• Increase the current flowing through the coil (using a higher voltage source within safe limit).

Using a soft iron core also helps the electromagnet to magnetize and demagnetize easily.

Answer: Increase the number of turns and increase the current in the coil.

17. WAEC Physics Question (Heat – Temperature Scale)

Convert 35 °C to the Kelvin scale and 310 K to the Celsius scale.

Solution:

K = °C + 273. So 35 °C = 35 + 273 = 308 K.

°C = K – 273. So 310 K = 310 – 273 = 37 °C.

Answer: 35 °C = 308 K; 310 K = 37 °C.

18. WAEC Physics Question (Heat – Specific Heat Capacity)

A 2 kg block of copper is heated from 20 °C to 50 °C. If the specific heat capacity of copper is 400 J kg^-1 K^-1, calculate the heat energy absorbed.

Solution: Heat energy, Q = mcΔT.

m = 2 kg, c = 400 J kg^-1 K^-1, ΔT = 50 – 20 = 30 K.

Q = 2 × 400 × 30 = 800 × 30 = 24 000 J.

Answer: 2.4 × 10⁴ J.

19. WAEC Physics Question (Modern Physics – Photoelectric Effect)

Mention two observations in the photoelectric effect that cannot be explained by the wave theory of light.

Solution / Answer:

• There is a threshold frequency below which no electron is emitted, no matter how intense the light is.
• The kinetic energy of emitted electrons depends on the frequency of the incident light, not on its intensity.

Also, the emission of electrons begins almost immediately when light of sufficient frequency falls on the metal, with no observable time lag.

Answer: Existence of threshold frequency and dependence of electron energy on frequency.

20. WAEC Physics Question (Modern Physics – Radioactivity)

A radioactive substance has a half-life of 5 days. If its initial activity is 800 counts per minute, what will be the activity after 15 days?

Solution: 15 days means 15/5 = 3 half-lives.

After each half-life, activity reduces by half:

• After 1st half-life: 800 / 2 = 400 cpm.
• After 2nd half-life: 400 / 2 = 200 cpm.
• After 3rd half-life: 200 / 2 = 100 cpm.

Answer: 100 counts per minute.

NECO Physics Past Questions and Answers (Fully Solved)

The following 15 questions follow the NECO SSCE style and cover key topics you will likely meet in 2024 and beyond.

1. NECO Physics Question (Mechanics – Momentum)

A 4 kg trolley moving with a velocity of 3 m s^-1 collides and sticks to a stationary 2 kg trolley. Find the common velocity after impact.

Solution: Momentum is conserved.

Initial momentum = (4 kg × 3 m s^-1) + (2 kg × 0) = 12 kg m s^-1.

Total mass after collision = 4 + 2 = 6 kg.

Let common velocity = v.

Final momentum = 6v.

Equate: 6v = 12 → v = 12/6 = 2 m s^-1.

Answer: 2 m s^-1.

2. NECO Physics Question (Mechanics – Pressure)

A block of area 0.2 m² rests on a horizontal floor. If its weight is 400 N, calculate the pressure it exerts on the floor.

Solution: Pressure, P = Force / Area.

P = 400 N / 0.2 m² = 2000 N m^-2 (Pa).

Answer: 2.0 × 10³ Pa.

3. NECO Physics Question (Mechanics – Centre of Gravity)

State two practical ways of locating the centre of gravity of an irregular lamina.

Solution / Answer:

• Hang the lamina freely from a point, allow it to rest, then draw a vertical line downwards from the point of suspension. Repeat for another point; the intersection of the lines is the centre of gravity.
• Balance the lamina on a sharp point and adjust until it is level; the point of support is approximately the centre of gravity.

Answer: Suspending method and balancing on a sharp point.

4. NECO Physics Question (Waves – Ripple Tank)

Mention two properties of water waves that can be demonstrated using a ripple tank.

Solution / Answer:

• Reflection of waves at a barrier.
• Refraction when waves pass from deep to shallow region.
• Diffraction when waves pass through a narrow gap.
• Interference when using two coherent sources.

Any two of the above earn full marks.

Answer: Reflection, refraction, diffraction or interference (any two).

5. NECO Physics Question (Sound – Characteristics)

Explain briefly the terms pitch and loudness of a sound.

Solution:

Pitch is the quality of sound that distinguishes high notes from low notes and it depends on the frequency of the sound wave.

Loudness is the quality that distinguishes loud sound from soft sound and it depends on the amplitude of the sound wave.

Answer: Pitch depends on frequency; loudness depends on amplitude.

6. NECO Physics Question (Light – Reflection)

The angle between an incident ray and the reflected ray from a plane mirror is 70°. Find the angle of incidence.

Solution: The angle between the incident and reflected rays is equal to (angle of incidence + angle of reflection).

But angle of incidence, i = angle of reflection, r.

So i + r = i + i = 2i = 70°.

i = 70°/2 = 35°.

Answer: 35°.

7. NECO Physics Question (Light – Magnification)

A converging lens forms an image of height 4 cm from an object of height 2 cm. Calculate the magnification and state the nature of the image.

Solution: Magnification, m = image height / object height = v/u in size terms.

m = 4 / 2 = 2.

Since magnification is greater than 1 and the image is real (for a converging lens producing larger image), the image is real, inverted and enlarged.

Answer: Magnification = 2; image is real, inverted and magnified.

8. NECO Physics Question (Electricity – Resistivity)

A metal wire of length 5 m and cross-sectional area 2.0 × 10^-6 m² has a resistance of 5 Ω. Calculate the resistivity of the material.

Solution: R = ρL/A, so ρ = RA/L.

R = 5 Ω, A = 2.0 × 10^-6 m², L = 5 m.

ρ = (5 × 2.0 × 10^-6) / 5 = 2.0 × 10^-6 Ω m.

Answer: 2.0 × 10^-6 Ω m.

9. NECO Physics Question (Electricity – Cells in Series)

Three identical cells each of e.m.f. 1.5 V are connected in series to a 3 Ω resistor. If the internal resistance of each cell is 0.5 Ω, calculate the current in the circuit.

Solution: Total e.m.f., E = 3 × 1.5 V = 4.5 V.

Total internal resistance, r = 3 × 0.5 Ω = 1.5 Ω.

External resistance, R = 3 Ω.

Total resistance in circuit = R + r = 3 + 1.5 = 4.5 Ω.

Current, I = E / (R + r) = 4.5 / 4.5 = 1.0 A.

Answer: 1.0 A.

10. NECO Physics Question (Electricity – Capacitors)

Two capacitors of 4 µF and 6 µF are connected in parallel across a 12 V battery. Calculate the total charge stored.

Solution: For parallel connection, C_eq = C₁ + C₂ = 4 + 6 = 10 µF.

Q = C_eqV = 10 µF × 12 V.

Convert µF to F: 10 µF = 10 × 10^-6 F.

Q = 10 × 10^-6 × 12 = 120 × 10^-6 C = 1.2 × 10^-4 C.

Answer: 1.2 × 10^-4 C.

11. NECO Physics Question (Heat – Latent Heat)

The specific latent heat of fusion of ice is 3.3 × 10⁵ J kg^-1. How much heat is required to melt completely 0.2 kg of ice at 0 °C to water at 0 °C?

Solution: Q = mL.

m = 0.2 kg, L = 3.3 × 10⁵ J kg^-1.

Q = 0.2 × 3.3 × 10⁵ = 0.66 × 10⁵ J = 6.6 × 10⁴ J.

Answer: 6.6 × 10⁴ J.

12. NECO Physics Question (Heat – Gas Laws)

A fixed mass of gas has a volume of 0.03 m³ at a pressure of 150 kPa. If the temperature remains constant, calculate its volume when the pressure is increased to 250 kPa.

Solution: Boyle's law: P₁V₁ = P₂V₂.

Given P₁ = 150 kPa, V₁ = 0.03 m³, P₂ = 250 kPa.

V₂ = (P₁V₁) / P₂ = (150 × 0.03) / 250.

150 × 0.03 = 4.5, so V₂ = 4.5 / 250 = 0.018 m³.

Answer: 0.018 m³.

13. NECO Physics Question (Modern Physics – X-rays)

State two uses and one hazard of X-rays.

Solution / Answer:

• Uses:
  • In medicine, to take radiographs of bones and teeth.
  • In industry, to check for cracks and flaws in metal castings (non-destructive testing).
• Hazard: Excessive exposure can damage body cells and cause cancer or lead to genetic mutations.

Answer: Medical imaging and industrial testing (uses); damage to body cells / cancer (hazard).

14. NECO Physics Question (Modern Physics – Nuclear Energy)

Differentiate between nuclear fission and nuclear fusion.

Solution:

Nuclear fission is the splitting of a heavy nucleus (such as uranium-235) into two or more lighter nuclei with the release of a large amount of energy.

Nuclear fusion is the combining of two light nuclei (such as hydrogen isotopes) to form a heavier nucleus with the release of even more energy.

Answer: Fission: splitting of heavy nucleus; fusion: combination of light nuclei.

15. NECO Physics Question (Modern Physics – Radioactive Decay)

The half-life of a radioactive element is 2 hours. If the initial number of atoms is 6400, how many atoms will remain after 6 hours?

Solution: 6 hours means 6/2 = 3 half-lives.

After 1st half-life: 6400 / 2 = 3200 atoms.

After 2nd half-life: 3200 / 2 = 1600 atoms.

After 3rd half-life: 1600 / 2 = 800 atoms.

Answer: 800 atoms.

Most Tested Topics in WAEC & NECO Physics (2020–2024 Trend)

From analysis of recent WAEC and NECO Physics papers in Nigeria, the following topics appear almost every year. Focus on them when using past questions:

• Mechanics
  • Motion under gravity, speed, velocity and acceleration.
  • Newton's laws of motion and momentum.
  • Work, energy, power and efficiency.
  • Machines (levers, pulleys, mechanical advantage, velocity ratio).
  • Pressure in liquids, density and flotation.
• Waves and Sound
  • Basic wave parameters (frequency, period, wavelength, speed).
  • Ripple tank experiments (reflection, refraction, diffraction, interference).
  • Sound waves, echo, reverberation, speed of sound.
• Light and Optics
  • Reflection in plane and curved mirrors.
  • Refraction, refractive index and critical angle.
  • Lenses (image formation, magnification, lens formula).
  • Optical instruments (camera, microscope, eye defects).
• Electricity and Magnetism
  • Ohm's law, resistors in series and parallel.
  • Power and electrical energy (kWh calculations).
  • Cells, internal resistance and combination of cells.
  • Electromagnetism (electric bell, relay, d.c. motor).
• Heat and Thermodynamics
  • Temperature scales and thermometers.
  • Expansion of solids and liquids.
  • Specific heat capacity and latent heat.
  • Gas laws (Boyle's, Charles' and Ideal gas equation).
• Modern Physics
  • Photoelectric effect and quantum theory.
  • X-rays, radioactivity, half-life and nuclear reactions.

WAEC & NECO Physics Exam Tips for Nigerian Students

1. How to Handle Calculations in Physics

• Read the question twice before you start. Underline key values and what you are asked to find.
• Write the formula first before substituting. Example: v = u + at, P = VI, Q = mcΔT.
• Check units and convert to S.I. units (m, kg, s) before calculation.
• Substitute carefully and show all steps. WAEC & NECO give marks for correct method even if your final answer is wrong.
• Round off properly (usually to 2 or 3 significant figures) and include units.
• Use your calculator wisely: avoid pressing too fast; re-check by doing the sum again quickly.

2. Important Units and Dimensions to Remember

• Force, F: unit = newton (N) = kg m s^-2.
• Work / Energy, W: unit = joule (J) = N m = kg m² s^-2.
• Power, P: unit = watt = J s^-1 = kg m² s^-3.
• Pressure, P: unit = pascal (Pa) = N m^-2.
• Charge, Q: unit = coulomb (C) = A s.
• Potential difference, V: unit = volt (V) = J C^-1.
• Resistance, R: unit = ohm (Ω) = V A^-1.
• Frequency, f: unit = hertz (Hz) = s^-1.
• Specific heat capacity, c: unit = J kg^-1 K^-1.
• Latent heat, L: unit = J kg^-1.

3. Common Physics Mistakes in WAEC & NECO (and How to Avoid Them)

• Forgetting units: Many students lose marks because they write only numbers. Always attach correct units to your final answer.
• Wrong conversion of units: For example, mixing cm and m, or hours and seconds. Practice changing cm to m, g to kg, minutes to seconds.
• Not showing working: Examiners give method marks. Even if your calculator gives wrong value, you can still score marks if working is clear.
• Skipping graph questions: Graph questions carry high marks. Learn how to choose scale, plot points, draw best fit line and find slope.
• Poor diagrams: In optics, mechanics and electricity, neat labelled diagrams make your answers clearer and earn marks.
• Memorizing without understanding: Understand why formulas work and practice many past questions. WAEC & NECO often twist questions.

Conclusion: You Can Pass WAEC & NECO Physics with Confidence

Physics is not only for “very brilliant” students. With steady practice of WAEC and NECO Physics past questions, clear understanding of formulas and good exam technique, any serious SS3 student in Nigeria can pass very well.

Use this guide to:

• Practice questions topic by topic.
• Mark yourself honestly and note where you are weak.
• Revise the most tested areas again and again.

Do not wait till exam week. If you start now and keep solving problems daily, you will enter the WAEC or NECO hall with boldness, knowing that you have already seen and solved similar questions before.

Keep practising, stay focused, and you will succeed!