8 5 The photograph shows a statue of Buddha in Sri Lanka, which is protected by a lightning conductor. © Valery Shanin/123RF (a) During a storm, a potential difference of 2.7 MV was generated between a cloud and the top of the lightning conductor on the statue. A flash of lightning passed between the cloud and the lightning conductor, producing a current of 25 kA for a time of 7.5 ms. Calculate the energy transferred by the lightning strike. (3) .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. Energy transferred = ....................................................... 9 Turn over (b) The lightning conductor is a length of copper wire with a diameter of 1.2 × 10–2 m and a resistance of 4.3 × 10−3 Ω. It runs along the back of the statue from the base to a height of 1.5 m above the top of the statue. A guidebook claims that the statue is over 30 m high. Assess the validity of this claim. resistivity of copper = 1.7 × 10−8 Ω m (4) .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................. (c) Give a reason why the lightning conductor should be taller than the statue. (1) .................................................................................................................................................................................................................................................. .................................................................................................................................................................................................................................................. (Total for Question 5 = 8 marks)