Physics Exam Past Questions and Answers | JAMB, WAEC and NECO

Physics is the science that studies the nature and properties of matter and energy. It covers topics like motion, heat, light, sound, electricity, magnetism, and the structure of atoms.

• Question 781: A radioactive substance has a half-life of 20 hours. What fraction of the original radioactive nuclei will remain after 80 hours? Options:
  A) 1/32
  B) 1/16
  C) 1/8
  D) 1/4
  E) 1/2
  Show Answer
  The correct answer is B .
• Question 782: Calculate the upthrust on an object of volume 50cm³ which is immersed in liquid of density 103kgm^-3 [g = 10ms^-2] Options:
  A) 0.8N
  B) 2.5N
  C) 0.5N
  D) 1.0N
  Show Answer
  The correct answer is C .
• Question 783:

  A carstarts from rest and covers a distance of 40 m in 10 s. Calculatethe magnitude of its acceleration

  Options:
  A) 3.20 ms${}^{-2}$
  B) 0.25 ms${}^{-2}$
  C) 0.80 ms${}^{-2}$
  D) 4.00 ms${}^{-2}$
  Show Answer
  The correct answer is C .
• Question 784: An electric device is rated 2000W, 250V. Calculate the maximum current it can take Options:
  A) 9A
  B) 8A
  C) 7A
  D) 6A
  Show Answer
  The correct answer is B .
• Question 785: Which of the following is true of sounds? Options:
  A) sound travels faster in air at 20^oC than at 30^oC
  B) the frequency of a given sound wave changes when it crosses the boundary seperating two media
  C) the wavelength of a given sound wave in air decreases as the temperature increases
  D) sound waves cannot be reflected
  Show Answer
  The correct answer is C .
• Question 786: An object is placed at 5.6 x 10^-4m in front of a converging lens of focal length 1.0 x 10^-nm. The image formed is Options:
  A) Real, Erect and magnified
  B) Virtual, erect and magnified
  C) Real, inverted and magnified
  D) Virtual, erect and diminished
  Show Answer
  The correct answer is C .
• Question 787: How much heat is absorbed when a block of copper of mass 0.05kg and specific heat capacity 390Jkg^-1K^-1 is heated from 20^oC to 70^oC? Options:
  A) 39 . 98 x 10^-1J
  B) 9.75 x 10²J
  C) 3.98 x 10³J
  D) 9.75 x 10³J
  Show Answer
  The correct answer is B .
• Question 788: The primary aim in high tension transmission is to Options:
  A) minimize electrical energy losses due to heat production
  B) increase the rate of energy transfer by using high voltage
  C) increase the current in the wire
  D) generate electricity at high current and low voltage
  Show Answer
  The correct answer is A .
• Question 789: A 40-W instrument has a resistance of 90$\mathrm{\Omega }$. On what voltage should it be operated normally? Options:
  A) 60V
  B) 150V
  C) 225V
  D) 3600V
  Show Answer
  The correct answer is A .
• Question 790:

  The diagram shows four positions of the bob of a simple pendulum. At which of these positions does the bob have maximum kinetic energy and minimum potential energy

  Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is B .