Energy resourcesIB MYP Physics: Subtopic test

1. 1
   A country that gets most of its electricity from one old coal-fired power station is planning to add wind turbines and solar panels to its energy mix.

   (a)

   Which of these is a non-renewable energy resource?

   [1 mark]

   • AWind
   • BTidal movement
   • CUranium used in nuclear power stations
   • DBiomass

   (b)

   Which sequence shows the main energy transfers in a coal-fired power station?

   [1 mark]

   • Achemical (coal), thermal, kinetic (turbine), electrical
   • Bchemical (coal), electrical, thermal, kinetic
   • Cnuclear, thermal, kinetic, electrical
   • Dthermal, chemical, kinetic, electrical

   (c)

   Explain why wind turbines are less reliable than a coal-fired power station.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A mountain region in Switzerland has a pumped-storage hydroelectric station. Two reservoirs, one high up the mountain and one in the valley below, are joined by pipes containing a pump and a turbine. At night, when demand for electricity is low, surplus electricity from the grid is used to pump water up to the upper reservoir. During the evening peak in demand, the water is released back down.

   (a)

   In which energy store does the water in the upper reservoir hold energy?

   [1 mark]

   • AThermal
   • BChemical
   • CGravitational potential
   • DKinetic

   (b)

   Why is pumped storage useful for the electricity grid?

   [1 mark]

   • AIt produces electricity without any energy being used for pumping
   • BIt stores surplus electrical energy to use at times of high demand
   • CIt increases the total amount of energy in the system
   • DIt burns fuel only when demand is low

   (c)

   Explain how electricity is generated when the water is released.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   Students investigate whether the number of blades on a model wind turbine affects the voltage it generates. They place the turbine 50 cm from a fan on the same speed setting and measure the voltage with a voltmeter. The voltage was 0.8 V with 2 blades, 1.1 V with 3 blades, 1.4 V with 4 blades, 1.5 V with 6 blades and 1.4 V with 8 blades.

   (a)

   State a testable hypothesis for this investigation, giving a scientific reason, and name one variable that must be controlled.

   [3 marks]

   (b)

   Evaluate the hypothesis using the results, and suggest one improvement to the method.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A small Pacific island nation generates all of its electricity by burning imported diesel in generators. The government is considering replacing most of the diesel generators with wind turbines and solar panels. The island has steady trade winds and strong sunshine, but it is occasionally hit by cyclones and has little spare flat land.

   (a)

   Describe how electricity is generated using a wind turbine, and explain how this differs from generating electricity in a coal- or gas-fired power station.

   [6 marks]

   (b)

   Discuss and evaluate the government's plan to replace most of the diesel generators with wind turbines and solar panels.

   [6 marks]

   Total for question 4: 12 marks

End of questions