1. Charge, potential difference, energy and current

2. What does it mean if something is described as charged? (1 mark)
List 3 ways that static electricity is used in industry? …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………(3 marks)
For one of the above examples, describe how the process works. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….(4 marks)
What is the equation that links charge, current and time? (1mark)
What is the equation that links charge, potential difference and energy? (1 mark)
How much charge flows when a current of 2A flows for 30 seconds? (1mark)
What current flows if a charge of 300C flows for 3minutes? …………………………………… (1 mark)
What current flows if a charge of 270C flows for 106seconds? ……………………………………………………………………………….(1 mark)
A p.d. of 12V is applied across a resistor. 250C of charge passes. How much energy was dissipated by the resistor ? … (1 mark)
A current of 0.12A flows through a resistor of 150 Ohms, 300C of charge passes. How much energy was dissipated by the resistor? … (2 marks)
A light bulb releases 230J of energy when connected to a 11V battery. How much charge flowed in the circuit? ………………………………………………………………………….……(1 mark)

3. The diagram shows a charged thundercloud.
(a) Why does the tree below the thundercloud become positively charged?
(1 mark)
(b) The base of the cloud has a negative charge of 18 coulombs.
The potential difference between the base of the cloud and the ground is kilovolts.
(i) Write down the equation that links charge, energy transferred and potential difference.
(1 mark)

4. (ii) Calculate the maximum energy that could be transferred to the ground by a lightning
strike. Show clearly how you work out your answer.
Maximum energy transferred =……………………………… joules
(2 marks)
(c) A lightning conductor is usually attached to tall buildings. This reduces the risk of damage by a lightning strike.
Explain why the lightning conductor is made of copper.
(2 marks)