WAEC Physics 2013 past questions

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

Ten questions from the 2013 WAEC Physics paper, with answers and explanations. We hold 48 questions from this paper, and the Skolra app has all of them.

WAEC Physics 2013 questions and answers

1.An electric heater has a resistance of 50 $\Omega$ . When it is immersed in water and connected to mains source, it draws a current of 4.0A. Calculate the heat gained by the water if the heater is switched on for 2 minutes, assuming no heat losses to the surroundings
1. A
  9,600 J
2. B
  192,000 J
3. C
  48,000 J
4. D
  96,000 J
  Correct
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Answer: D
Heat generated by the electric heater:
Q = I²Rt
where I = 4.0 A, R = 50 Ω, t = 2 min = 120 s
Q = (4.0)² × 50 × 120 = 16 × 50 × 120 = 96,000 J
Since no heat is lost to the surroundings, all 96,000 J is gained by the water.
2.the equation of a certain progressive transverse wave is y = 2 sin 2 $\pi ( \frac{1}{0.01} - \frac{x}{30})$ , where x and y are in cm and t in seconds. Calculate the period of the wave
1. A
  30 s
2. B
  0.01 s
  Correct
3. C
  0.10 s
4. D
  0.02 s
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Answer: B
The standard form of a progressive wave is:
y = A sin 2π(t/T − x/λ)
Comparing with y = 2 sin 2π(t/0.01 − x/30):
The period T = 0.01 s, and the wavelength λ = 30 cm.
3.The total area under a force-velocity graph represents
1. A
  impulse
2. B
  work done
3. C
  kinetic energy
4. D
  power
  Correct
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Answer: D
At any point on a force–velocity graph, the product F × v gives power (P = Fv).
Consequently the total area under the graph has dimensions of [N] × [ms⁻¹] = W, representing power. (Compare: area under F–t gives impulse; area under F–x gives work done.)
4.Which of the following radiations has its frequency lower than that of infrared radiation?
1. A
  ultraviolet
2. B
  visible light
3. C
  X-rays
4. D
  radio waves
  Correct
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Answer: D
The electromagnetic spectrum in order of increasing frequency is:
Radio waves → Microwaves → Infrared → Visible → UV → X-rays → Gamma rays
Radio waves have a lower frequency (and longer wavelength) than infrared radiation. Visible light, UV, and X-rays all have higher frequencies than infrared.
5.The rising of a liquid in an open and ended glass tube of narrow bore is
1. A
  capillarity
  Correct
2. B
  osmosis
3. C
  diffusion
4. D
  viscosity
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Answer: A
The rise (or fall) of a liquid in a narrow tube (capillary tube) is called capillarity (or capillary action).
It is caused by the combined effects of adhesion (liquid–glass attraction) and cohesion (liquid–liquid attraction), which together produce a net surface tension force that draws the liquid up the tube.
6.a charge of 2.0 x 10^-5C experiences a force of 80N in a uniform electric field. Calculate the magnitude of the electric field intensity
1. A
  4.0 × 10³ N C⁻¹
2. B
  4.0 × 10⁶ N C⁻¹
  Correct
3. C
  1.6 × 10⁻³ N C⁻¹
4. D
  1.6 × 10³ N C⁻¹
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Answer: B
Electric field intensity is defined as force per unit charge: E = F / q
E = 80 / (2.0 × 10⁻⁵) = 4.0 × 10⁶ N C⁻¹
7.Which of the following statements about waves in pipes is correct?
1. A
  a closed pipe produces only odd harmonics
  Correct
2. B
  both open and closed pipes produce the same set of harmonics
3. C
  a closed pipe produces all harmonics
4. D
  an open pipe produces only odd harmonics
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Answer: A
In a closed pipe (closed at one end), a node forms at the closed end and an antinode at the open end. Only an odd number of quarter-wavelengths fit, so only the fundamental and odd harmonics (1st, 3rd, 5th, …) are produced.
An open pipe (open at both ends) produces all harmonics (1st, 2nd, 3rd, …).
8.Which of the following units is equivalent to the watt?
1. A
  Js⁻¹
  Correct
2. B
  Js
3. C
  Jm
4. D
  Jm⁻¹
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Answer: A
Power is defined as the rate of doing work (energy transferred per unit time):
1 W = 1 J / 1 s = 1 Js⁻¹
Therefore the watt is equivalent to Js⁻¹ (joules per second).
9.
A body of mass 20g projected vertically upwards in vacuum returns to the point of projection after 1.2s. [g = 10ms^-2]. Determine the potential energy of the body at the maximum height of its motion
1. A
  0.18 J
2. B
  3.6 J
3. C
  0.36 J
  Correct
4. D
  0.72 J
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Answer: C
Total flight time = 1.2 s, so time to reach maximum height = 0.6 s.
Initial speed: u = gt = 10 × 0.6 = 6 ms⁻¹
At maximum height all kinetic energy converts to potential energy:
PE = ½mu² = ½ × 0.020 × 6² = ½ × 0.020 × 36 = 0.36 J
10.The minimum energy required to cause photoelectric emission when the surface of a metal is irradiated with electromagnetic radiation of suitable frequency is called
1. A
  Kinetic energy of the photoelectron
2. B
  Work function
  Correct
3. C
  Threshold frequency
4. D
  Ionization energy
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Answer: B
The work function (symbol φ) is the minimum energy required to eject an electron from the surface of a metal when irradiated with electromagnetic radiation. It represents the energy needed to overcome the binding forces at the metal surface. Einstein's photoelectric equation is: hf = φ + KE_max, where hf is the photon energy and KE_max is the maximum kinetic energy of the emitted electron.

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WAEC Physics 2013 past questions

WAEC Physics 2013 questions and answers

Practise all 48 questions we hold from the 2013 paper, on a timed CBT screen

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