AQA GCSE COMBINED SCIENCE: TRILOGY 8464/P/1F Foundation Tier Physics Paper 1F Question Paper + Mark

junp1f01* IB/M/Jun20/E13 8464/P/1F A student investigated how the resistance of a wire varies with the length of the wire. Figure 1 shows the circuit used. Figure 1 box . The symbols for the voltmeter and ammeter in Figure 1 are not complete. Complete the symbols for the voltmeter and ammeter in Figure 1. [1 mark] . Which variable is the independent variable? Tick ( ) one box. The current in the wire [1 mark] The length of the wire being tested The resistance of the wire The thickness of the wire . Which variable is the dependent variable? Tick ( ) one box. The current in the wire [1 mark] box The length of the wire being tested The resistance of the wire The thickness of the wire . The student took repeat readings of potential difference for a 30 cm length of the wire. The readings were: 0.16 V 0.17 V 0.15 V Calculate the mean potential difference. [2 marks] Mean potential difference = V Question 1 continues on the next page Turn over ► The length of the wire was increased to 60 cm The current in the wire was 0.50 A The mean potential difference across the wire was 0.32 V box . Calculate the resistance of the 60 cm length of wire. Use the equation: resistance = potential difference current [2 marks] Resistance = Ω . Calculate the power dissipated in the 60 cm length of wire. Use the equation: power = potential difference × current [2 marks] Power = W . Calculate the charge flow when there is a current of 0.50 A in the wire for 17 s Use the equation: box charge flow = current × time [2 marks] Charge flow = C . Figure 2 is a sketch graph of the results. Figure 2 The student repeated the investigation using a thicker wire made from the same metal. For the same length, the thicker wire has a lower resistance. Draw a line on Figure 2 to show how the resistance of the thicker wire varies with length. [1 mark] Turn over for the next question Turn over ► Between 1951 and 1992 the USA tested nuclear weapons in a desert. box . Complete the sentence. Choose the answer from the box. [1 mark] Radioactive dust from the nuclear weapons testing settled on the desert. This is called radioactive . The desert now contains radioactive tritium. Figure 3 shows how the activity of the tritium in a sample taken from the desert changed with time. Figure 3 . The sample was collected from the desert in 1992. Determine the activity of the tritium in the sample in 2007. [2 marks] box Activity = Bq . How much time did it take for the activity of the tritium in the sample to decrease from 80 Bq to 40 Bq? [1 mark] Time = years . What is the half-life of tritium? [1 mark] Half-life = years . The sample started with 45 billion atoms of tritium. After 4 years the sample had 36 billion atoms of tritium. Calculate the percentage of the tritium in the sample that remained after 4 years. [2 marks] Percentage of tritium remaining = % Turn over ► . A scientist determined the activity of a sample of tritium every minute for 3 minutes. Table 1 shows the results. Table 1 box Time in minutes Activity in Bq 0 149 1 151 2 148 3 152 Why do the activity readings in Table 1 vary? Tick ( ) one box. Radioactive decay is a random process. [1 mark] Temperature changes affect the radioactive decay. The number of radioactive nuclei keeps increasing and decreasing. . What safety precaution should scientists take when working with radioactive materials in a laboratory? [1 mark] Tick ( ) one box. Tie long hair back before handling the materials. Use long tongs to handle the materials. Wear safety goggles when handling the materials. . Studies show that children born near the area of the desert containing tritium were more likely to develop cancer. It is important that the results from these studies are checked by other scientists. box What is this process called? Tick ( ) one box. Experiment review [1 mark] Peer review Results review Test review Turn over for the next question Turn over ► An eco-house is designed to be environmentally friendly. Figure 4 shows a picture of an eco-house. Figure 4 . The solar panels and a wind turbine are used to generate electricity for the eco-house. Solar and wind are both renewable energy resources. What does renewable energy resource mean? Tick ( ) one box. It can be replenished as it is used. [1 mark] box It is unreliable. It has no fuel costs. It produces no greenhouse gases. . Biomass, nuclear and natural gas are three other energy resources. Complete the table to show whether each energy resource is renewable or non-renewable. Tick ( ) one box for each energy resource. Energy resource Renewable Non-renewable Biomass Nuclear Natural gas . Moving air makes the wind turbine spin. The wind turbine generates electricity which is used to charge a battery. Complete the sentences. Choose answers from the box. [2 marks] [2 marks] box When the wind turbine spins faster there is an increase in its energy. Charging the battery increases the store of energy of the battery. Question 3 continues on the next page Turn over ► . The roof of the eco-house is covered with soil. Covering the roof with soil decreases the thermal conductivity of the roof. What are the advantages of having a roof with a lower thermal conductivity? Tick ( ) two boxes. Less energy is needed to heat the house. [2 marks] box The rate of energy transfer by conduction is greater. The roof is a better insulator. The roof is less likely to leak. Weather will have a greater effect on the temperature of the house. . The average power transferred to the solar panels by sunlight is 26 000 W Calculate the average energy transferred to the solar panels in 30 seconds. Use the equation: energy transferred = power × time [2 marks] Average energy transferred to solar panels = J . Write down the equation that links efficiency, total power input and useful power output. [1 mark] box . The solar panels on the roof of the eco-house have an efficiency of 0.15 The average power input to the solar panels is 26 000 W Calculate the average useful power output from the solar panels. [3 marks] Average useful power output = W