WAEC Physics 2021 past questions

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

Ten questions from the 2021 WAEC Physics paper, with answers and explanations. We hold 65 questions from this paper, and the Skolra app has all of them.

WAEC Physics 2021 questions and answers

1. 1.

   Which of the following quantities is not an example of force?

   1. A
      friction
   2. B
      tension
   3. C
      weight
   4. D
      momentum
      Correct
   Show answerHide answer

   Answer: D

   Momentum (mv) is a vector quantity with different dimensions than force. Force causes changes in momentum, but momentum itself is not a force.

2. 2.

   An ice cube has mass of 20 g at 5°C. Calculate the energy required to raise its temperature to 0°C. [Specific heat capacity of ice = 2.1 J/g°c]

   1. A
      420 J
   2. B
      1050 J
      Correct
   3. C
      840 J
   4. D
      525 J
   Show answerHide answer

   Answer: B

   Heat energy required is calculated using Q = mcΔT. With the given specific heat capacity of ice, the energy varies with temperature change.

3. 3.

   The components of vectors Q and R are (-3.0, 5.5) and (9.2, 4.4) respectively. Determine the components of Q + R.

   1. A
      (6.2, 9.9)
      Correct
   2. B
      (6.2, -0.9)
   3. C
      (-6.2, 9.9)
   4. D
      (6.2, -9.9)
   Show answerHide answer

   Answer: A

   Vector addition is performed by adding corresponding components. The x-components add together, as do the y-components.

4. 4.

   Which of the following statements about the universal gravitational constant, G, is true?

   1. A
      it is a constant for all gravitational interactions
      Correct
   2. B
      it is different on different planets
   3. C
      it is proportional to distance between objects
   4. D
      it varies with mass of the objects
   Show answerHide answer

   Answer: A

   The universal gravitational constant G is a fundamental constant that doesn't vary with mass, distance, or location.

5. 5.

   An electric pressing iron is connected to the mains using an insulated wire. wire becomes very hot.

   The heat generated in the wire can be minimized by replacing the wire with one of?

   1. A
      an aluminum wire of the same length
   2. B
      a thicker wire of the same material
      Correct
   3. C
      copper wire of the same length
   4. D
      a shorter insulated wire
   Show answerHide answer

   Answer: B

   Using H = I²Rt, reducing resistance R minimizes heat. A thicker wire has smaller resistance, thus less heat generation.

6. 6.

   An atom that emits an a-particle?

   1. A
      decreases its atomic number by 2
      Correct
   2. B
      increases its atomic number by 2
   3. C
      increases its mass number by 4
   4. D
      stays in the same position in the periodic table
   Show answerHide answer

   Answer: A

   Alpha decay emits a helium-4 nucleus, reducing atomic number by 2 and moving the element two positions back in the periodic table.

7. 7.

   Opening in the eye through which light passes to the retinais called the?

   1. A
      pupil
      Correct
   2. B
      lens
   3. C
      iris
   4. D
      cornea
   Show answerHide answer

   Answer: A

   The pupil is the opening in the iris that allows light to pass through to the retina. Its size is controlled by the iris muscles to regulate light intensity.

8. 8.

   A wire of cross-sectional area 2π *10$^-{8}$m$2$ and resistivity 1.1 x 10$^-{8}$Ω m, has a resistance of 21Ω.

   Calculate the length of the wire. [π=22/7]

   1. A
      1.0 m
   2. B
      1.5 m
   3. C
      0.5 m
   4. D
      2.0 m
      Correct
   Show answerHide answer

   Answer: D

   Using R = ρL/A, we can solve for length: L = RA/ρ. The specific values calculate to approximately 2.0 m.

9. 9.

   The handle of a screw jack is 35 cm long andpitch of the screw is 0.5 cm. What force must be applied at the end of the handle to lift a load of 2000N,if the efficiency of the jack is 30% [π = 22/7]?

   1. A
      60 N
   2. B
      15 N
   3. C
      30 N
      Correct
   4. D
      45 N
   Show answerHide answer

   Answer: C

   The screw jack's mechanical advantage depends on handle length and pitch. With 30% efficiency, the actual force needed is greater than ideal.

10. 10.

    The distance between a node and its adjacent antinode of a transverse wave is equal to?

    1. A
       λ
    2. B
       ¼λ
       Correct
    3. C
       2λ
    4. D
       ½λ
    Show answerHide answer

    Answer: B

    Standing wave patterns show nodes (zero amplitude) and antinodes (maximum amplitude) spaced λ/4 apart. This spacing is fundamental to wave behavior.

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

Spotted a wrong answer? Tell us from the app or on the contact page and we check it.

Practise all 65 questions we hold from the 2021 paper, on a timed CBT screen

Every question has the answer and an explanation, in the Skolra app.

Download for WindowsDownload for Mac

About the app · Skolra for Windows · Skolra for Mac