2025 WAEC GCE Physics Questions and Answers

1. Complete the table below by placing the given magnetic materials in the correct column.
Materials: Aluminum, Cobalt, Iron, Nickel, Platinum, Sodium.

[3 marks]

2. The diagrams below illustrate wave rectification by a diode.

[Insert Diagram: Input signal wave, Circuit with transformer and diode, Output signal wave]

(a) What type of wave rectification is illustrated?

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(b) What type of electrical signal is the output voltage?

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(c) Identify the electrical symbol labeled X.

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[3 marks]

3. Explain the term absorption spectrum as it relates to light.

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[3 marks]

4. The diagram below illustrates the energy levels of a hydrogen atom.

If an electron in the first excited state emits photons as it drops to the ground state, calculate the energy of the photons emitted in joules.
[1eV = 1.6 x 10^-19J]

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[3 marks]

5. The moment of inertia, I, is given by:

I = ^{(distance)2 × weight × 9 (period)2} ⁄ _{16 × π² × Length}

Derive the dimensions of I.

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6. A 10m long plane is inclined at an angle of 30° with the horizontal. A ball placed at the upper end rolled down the length of the inclined plane. How long will it take the ball to cover the entire length of the plane?
[g = 10 ms^-2]

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[3 marks]

7. Draw a labeled ray diagram to illustrate the image of an object placed between the principal focus and the pole of a concave mirror.

[Space for Ray Diagram]

[3 marks]

8. (a) (i) Give one difference between a resultant force and an equilibrant force.

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(ii) The diagram below illustrates a uniform sphere of mass 4 kg kept in position by two strings WX and YZ. WX is horizontal while YZ is inclined at 40° to the horizontal. Calculate the tension in each string.

[Insert Diagram: Sphere hanging from strings WX and YZ, angle 40°]

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[4 marks]

(iii) Three forces act on a point as shown in the illustration below. Calculate the magnitude and direction of the equilibrium force.

[Insert Diagram: Point with forces 4N left, 5N right, 7N inclined at 35°]

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[4 marks]

(b) (i) State two differences between a particle motion and wave motion.

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[2 marks]

(ii) The diagrams below illustrate velocity-time graphs.

Use the diagram to describe the acceleration in each case.

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II. _______________________________________________________________________

[3 marks]

9. (a) (i) State three differences between sensible heat and latent heat.

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[3 marks]

(ii) State two natural sources of heat energy.

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[2 marks]

(iii) Mention two advantages of mercury over alcohol as thermometric substances.

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[2 marks]

(b) (i) A resistance thermometer reads 10 Ω when placed in melting ice and 110 Ω when placed in steam. Calculate the temperature of a liquid at which the thermometer reads 75 Ω.

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[3 marks]

(ii) An effective electric heater rated at 60 Watts was able to heat 150 g of water in a calorimeter from 60°C to 107°C. Determine the time taken in minutes for current to flow during the heating process.
[Specific heat capacity of water is 4200 J kg^-1 K^-1]

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[3 marks]

(iii) State two factors that heat capacity and cooling process have in common.

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[2 marks]

10. (a) (i) Mention three differences between stationary wave and progressive wave.

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[3 marks]

(ii) A plane progressive wave has amplitude of 6 m and a velocity of 110 ms^-1. If the frequency of the wave is 160 Hz, write down the progressive wave equation.

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[3 marks]

(iii) Define the following terms as they relate to wave motion:

I. harmonic;
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II. overtone.
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(b) (i) Write down the equation showing the relationship between the refractive index μ, minimum deviation D_m and refracting angle A of a triangular glass prism.

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[4 marks]

(ii) The refracting angle in a triangular glass prism is 50°. If the index of refraction of the prism is 1.41, determine the minimum deviation of a ray of light passing through it.

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[3 marks]