Past Questions And Answers
An object falls freely from a height of 25m onto the roof a building 5m high. Calculate the velocity with which the object strikes the roof (g=10\(ms^{-2}\)
- A. 17.3\(ms^{-2}\)
- B. 20\(ms^{-2}\)
- C. 24.5\(ms^{-2}\)
- D. 125\(ms^{-2}\)
The earth's movement from west to east on its own axis is known as
- A. rotation
- B. revolution
- C. friction
- D. gravitation
the person who brought the leader of al murabbitun to west africa was
- A. Yahya b. Ibrahim
- B. Abdullah b. yasin
- C. Umar al-futi
- D. Idris Alooma
(a)(i) Explain photoelectric emission.
(ii) State four applications of photoelectric emission.
(b) Draw and label a diagram showing the structure of a simple type of a photocell and explain its mode of operation.
(c) In a photocell, no electrons are emitted until the threshold frequency of light is reached.
(i) Explain what happens to the energy of the light before emission of electrons begin.
(ii) State one factor that may affect the number of emitted electrons.
View Discussion (0)WAEC 2003 THEORY.jpg)
The establishment of game reserves and parks is a method of
- A. conserving natural resources
- B. cultivating game
- C. controlling pollution
- D. cultural awareness
(a)(i) Outline the steps involved in the purification of water for town supply.
(ii) Give two cations that can cause hardness in water.
(iii) State two disadvantages of hardness of water.
(iv) List two sources of water pollution.
(b)(i) Explain briefly why water is a good solvent for sodium chloride but not for oil.
(ii) State the function of H\(_2\)SO\(_4\) in each of the following reaction equations:
(i) C\(_2\)H\(_5\)OH\(_{(l)}\) \(\to\) C\(_2\)H\(_{4(g)}\)
(ii) MgO\(_{(s)}\) + H\(_2\)SO\(_4\)\(_{(aq)}\) —> MgSO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\)
(iii) C\(_{(s)}\) + conc. H\(_2\)SO\(_4\) --> CO\(_{(g)}\) + SO\(_{2(g)}\) + H\(_2\)O\(_{(l)}\)
(c) (i) Give the two products formed when chlorine water is exposed to sunlight.
(ii) I. Which of the compounds is suitable for the preparation of standard alkaline solution?
II. Give a reason for your answer in (c)(ii)I
View Discussion (0)WAEC 2014 THEORYWhich of the following statements is correct about micro-nutrients? They
- A. promote formation of only root nodules
- B. are required by plants in very small quantities
- C. are fixed into the soil through microbial activity
- D. increase crop tolerance to pest attack
In the diagram, XYZ is an equilateral triangle of side 6cm and Y is the midpoint of \(\overline{XY}\). Find tan (< XZT)
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- A. \(\frac{1}{\sqrt{3}}\)
- B. \(\frac{\sqrt{3}}{2}\)
- C. \(\sqrt{3}\)
- D. \(\frac{1}{2}\)
Find the stationary point of the curve \(y = 3x^{2} - 2x^{3}\).
- A. (1, 0)
- B. (-1, 0)
- C. (1, 1)
- D. (-1, -1)
Which of the following accurately describes the rough endoplasmic reticulum and the smooth endoplasmic reticulum?
- A. The smooth endoplasmic reticulum has many ribosomes bound to its surface, but the rough endoplasmic reticulum does not.
- B. The rough endoplasmic reticulum has many ribosomes bound to its surface, but the smooth endoplasmic reticulum does not.
- C. Neither the rough endoplasmic reticulum nor the smooth endoplasmic reticulum have any ribosomes bound to their surfaces.
- D. The rough endoplasmic reticulum and the smooth endoplasmic reticulum both have many ribosomes bound to their surfaces.