JAMB Physics 2015 past questions

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

Ten questions from the 2015 JAMB Physics paper, with answers and explanations. We hold 70 questions from this paper, and the Skolra app has all of them.

JAMB Physics 2015 questions and answers

1. 1.The direction of the path taken by light is called
   1. A
      a ray
      Correct
   2. B
      a beam
   3. C
      a photon
   4. D
      a wave
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   Answer: A

   In geometrical optics, a ray is defined as a line that represents the direction of travel of light energy. It is an arrow drawn perpendicular to the wavefront, indicating the path along which light propagates.

   A beam is a collection of many rays. A wave describes the nature of light mathematically. A photon is a quantum (particle) of light energy.

2. 2.The strength of an electromagnet increase with
   1. A
      Decreasing the current through the coil
   2. B
      Using a hard steel core
   3. C
      Decreasing the number of coil turns
   4. D
      Increasing the current and the number of turns of the coil
      Correct
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   Answer: D

   The magnetic field strength of an electromagnet is directly proportional to the product of current I and the number of turns N (the ampere-turns). Increasing current and increasing the number of turns both raise the magnetomotive force and therefore the field strength. A soft iron core is preferred because it concentrates flux and is easily demagnetised; hard steel retains magnetism and is used for permanent magnets, not electromagnets.

3. 3.The symbol ₋₁⁰X used to represent which of the particles?
   1. A
      Alpha particle
   2. B
      Neutron
   3. C
      Electron
      Correct
   4. D
      Proton
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   Answer: C

   The notation ^{mass number}_{atomic number}X describes a nuclear particle by its mass number (top) and atomic number or charge (bottom). A mass number of 0 and a charge of −1 identifies the electron (beta-minus particle). A proton has charge +1 and mass number 1; a neutron has charge 0 and mass number 1; an alpha particle has charge +2 and mass number 4.

4. 4.What type of electromagnetic radiation can be used to take photographs in the haze?
   1. A
      Gamma rays
   2. B
      X-rays
   3. C
      Ultraviolet radiation
   4. D
      Infrared radiation
      Correct
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   Answer: D

   Infrared (IR) radiation has a longer wavelength than visible light and is less scattered by haze, mist, and atmospheric particles. This allows IR radiation to penetrate haze more effectively than visible light.

   Infrared photography is widely used in aerial and satellite imaging, as well as in photography under foggy or hazy conditions, because infrared wavelengths are not significantly scattered by the water droplets and particles that cause haze.

5. 5.

   Calculate the gravitation force of attraction between two planets of 10²⁴kg and 10²⁷kg separated by a distance of 10²⁰meters.

   1. A
      6.67 × 10⁻² N
   2. B
      6.67 N
      Correct
   3. C
      6.67 × 10⁻¹¹ N
   4. D
      6.67 × 10¹¹ N
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   Answer: B

   Newton's Law of Universal Gravitation: F = Gm₁m₂/r²

   Where G = 6.67 × 10⁻¹¹ N·m²/kg², m₁ = 10²⁴ kg, m₂ = 10²⁷ kg, r = 10²⁰ m.

   F = (6.67 × 10⁻¹¹ × 10²⁴ × 10²⁷) / (10²⁰)²
   = (6.67 × 10⁻¹¹⁺²⁴⁺²⁷) / 10⁴⁰
   = 6.67 × 10⁴⁰ / 10⁴⁰
   = 6.67 N

6. 6.What is the S.I unit of relative density?
   1. A
      kg/m³
   2. B
      It has no unit
      Correct
   3. C
      g/cm³
   4. D
      N/m²
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   Answer: B

   Relative density (also called specific gravity) is defined as the ratio of the density of a substance to the density of a reference substance (usually water). Because it is a ratio of two quantities with the same units, the units cancel and relative density is a dimensionless quantity — it has no SI unit.

7. 7.At what respective value of a, b, and c would the unit of work, the joule, be dimensionally similar to M^a L^b T^c?
   1. A
      a = 1, b = 1, c = −2
   2. B
      a = 2, b = 1, c = −2
   3. C
      a = 1, b = 2, c = −1
   4. D
      a = 1, b = 2, c = −2
      Correct
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   Answer: D

   Work = Force × Distance. The dimension of force is derived from Newton's second law:

   Force = mass × acceleration = [M][LT⁻²] = [MLT⁻²]

   Work = Force × Distance = [MLT⁻²] × [L] = [ML²T⁻²]

   Comparing with M^aL^bT^c:

   a = 1, b = 2, c = −2

8. 8.A structural engineer stood on a top of a building releasing a light and heavy object to the ground which of the following statement is true?(Neglect Air Resistance)
   1. A
      Both objects hit the ground at the same time
      Correct
   2. B
      The lighter object hits the ground first
   3. C
      The heavier object hits the ground first
   4. D
      The time of fall depends on the material of the object
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   Answer: A

   When air resistance is neglected, every freely falling object experiences the same gravitational acceleration g regardless of its mass. This was demonstrated by Galileo Galilei: a 1 kg and a 10 kg object released from the same height reach the ground simultaneously. The equation h = ½gt² contains no mass term, confirming that both objects take identical times to fall.

9. 9.Primary colours of light are
   1. A
      Cyan, Magenta, Yellow
   2. B
      Red, Green, Blue
      Correct
   3. C
      Red, Yellow, Blue
   4. D
      Red, Orange, Violet
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   Answer: B

   The primary colours of light (additive primaries) are Red, Green, and Blue (RGB). When combined in equal intensities, they produce white light.

   Mixing two primaries of light gives a secondary colour: Red + Green = Yellow; Green + Blue = Cyan; Red + Blue = Magenta.

   Note: Red, Yellow, Blue are the primary pigment (subtractive) colours used in painting, not light. Cyan, Magenta, and Yellow are the subtractive primaries used in printing.

10. 10.For a best result using temperature to achieve an accurate measurement, it is best to use
    1. A
       Alcohol-in-glass thermometer
    2. B
       Mercury-in-glass thermometer
    3. C
       Platinum resistance thermometer
       Correct
    4. D
       Clinical thermometer
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    Answer: C

    The platinum resistance thermometer is the most accurate temperature-measuring device because platinum has a very stable, well-characterised resistance-temperature relationship over a wide range (about −200 °C to 1200 °C). Its readings are reproducible to within thousandths of a degree, making it the international standard for precision temperature measurement.

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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