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 791:
  

  The fiqure above represents a block-and-tackle pulley system on which an effort of W Newtons supports a load of 120.0N. If the efficiency of the machine is 40${}^o$, then the value of W is

  Options:
  A) 28.0N
  B) 48.0N
  C) 288.0N
  D) 50.0N
  Show Answer
  The correct answer is D .
• Question 792:

  The point at which the molecules of a loaded wire begin to slide across each other resulting in a rapid increase in extension is

  Options:
  A) yield point
  B) proportionality point
  C) deformation point
  D) elastic point
  Show Answer
  The correct answer is A .
• Question 793: Which of the following expressions gives the linear magnification produced by a concave mirror of radius of curvature r, if U and V are the object and image distances respectively? Options:
  A) $\frac{V}{r}$ - 1
  B) $\frac{2V}{r}$ - 1
  C) $\frac{U}{r}$ - 1
  D) $\frac{2U}{r}$ - 1
  Show Answer
  The correct answer is D .
• Question 794: A positive charged rod X is brought near as uncharged metal sphere Y and is then touched by a finger with X still in place. When the finger is removed, the result is that y has Options:
  A) no charge and a zero potential
  B) a positive charge and zero potential
  C) a negative charge and positive potential
  D) a negative charge and a negative potential
  Show Answer
  The correct answer is D .
• Question 795:

  The refractive index of a liquid is 1.5. If the velocity of light in vacuum is 3.0 x 10${}^{8}m{s}^{-1}$, the velocity of light in the liquid is

  Options:
  A) 1.5 x 10${}^{8}m{s}^{-1}$
  B) 2.0 x 10${}^{8}m{s}^{-1}$
  C) 3.0 x 10${}^{8}m{s}^{-1}$
  D) 4.5 x 10${}^{8}m{s}^{-1}$
  Show Answer
  The correct answer is B .
• Question 796:

  A copper rod, 5m long when heated through 20c, expands by 1mm. If a second copper rod, 2.5m long is heated through 5c, by how much will it expand?

  Options:
  A) 4mm
  B) 2mm
  C) 0.25mm
  D) 0.12mm
  Show Answer
  The correct answer is B .
• Question 797: Natural radioactivity consists of the emission of Options:
  A) $\alpha$ -particle and $\beta$ rays
  B) $\alpha$ -particle and X-rays
  C) $\gamma$-rays and X-rays
  D) $\alpha$-particle, $\beta$ rays and $\gamma$-rays
  E) $\alpha$ -particle, $\beta$ rays, $\gamma$-rays and X-rays
  Show Answer
  The correct answer is D .
• Question 798: The pair of physical quantities that are scalar only are ? Options:
  A) volume and area
  B) moment and momentum
  C) length and displacement
  D) Impulse and time
  Show Answer
  The correct answer is A .
• Question 799: Calculate the heat energy lost when 10g of boiling water changes to ice at 0°C. [Specific latent heat of ice 336Jg^-1 . Specific heat capacity of water 4.2Jg^-1 K^-1] Options:
  A) 840J
  B) 3360J
  C) 3420J
  D) 4200J
  E) 7560J
  Show Answer
  The correct answer is E .
• Question 800: If a current of 2.5A flows through an electrolyte for 3 hours and 1.8g of a substance is deposited, what is the mass of the substance that will be deposited if a current of 4A flows through it for 4.8 hours? Options:
  A) 2.4g
  B) 3.2g
  C) 4.6g
  D) 4.8g
  Show Answer
  The correct answer is C .