cameroon gce intermediate level 2025 engineering science 2
cameroon gce intermediate level 2025 engineering science 2
Image 2: Structured Questions
2. (a)
Calculate:
(i) The total resistance in the circuit. (2 marks)
(ii) The potential difference across the 7 Ω resistor in the parallel section. (3 marks)
(iii) The current through the 3 Ω resistor. (1 mark)
(c)
(i) Give one advantage of A.C over D.C (1 mark)
(ii) Name a device used to store electric charges and draw its circuit symbol (2 marks)
(iii) In pre-paid meters installed by ENEO, a household buys energy before consumption. How many units (kWh) will the house hold receive after buying energy worth 7500 frs. (1 unit costs 75 frs) (2 marks)
3. (a)
(i) Give two properties of plastics which make them useful as engineering materials. (2 marks)
(ii) What is recycling of plastics? (1 mark)
(iii) What advantage does recycling of plastics have on the environment? (1 mark)
(b) Copy and complete the table by selecting a suitable metal from the box below, giving reason in each case.
[Box contains: Aluminium, Gold, Magnesium, Copper, Iron, Lithium]
| Uses | Metal | Property of material responsible for its use. |
|—|—|—|
| Earrings | | |
| Axe | | |
| Body work of aircraft | | |
(c)
(i) State Hooke’s law. (1 mark)
(ii) Sketch a force-extension graph for a material that obeys Hooke’s law for loads ranging up to the elastic limit. (2 marks)
(iii) The length of a wire that obeys Hooke’s law increases from 80 mm to 83 mm when a mass of 0.03 kg is suspended on it. The length increases to 94 mm, when another mass is added to it. Find the additional mass on the wire. (2 marks)
4. (a) Butane (C₄H₁₀) is the main component of cooking gas used in our homes.
(i) Write the structural formula of butane. (1 mark)
(ii) Write a balanced equation to show the complete combustion of butane. (3 marks)
(iii) Calculate the molar mass of butane given that C=12 and H=1. (2 marks)
(iv) How many moles are present in 11.6 g of Butane? (2 marks)
(b) What is electrolysis? (1 mark)
(c) A copper (II) sulphate solution was electrolyzed using inert electrodes.
(i) State the different ions present in the solution. (2 marks)
(ii) Given that a steady current of 2 A was passed through the solution for 1 hour 40 minutes, calculate:
(i) The quantity of charge passed. (2 marks)
(ii) The number of Faradays used. (2 marks)
