8.1. Define current strength. 8.2 R Switch S Study the diagram above and identify a voltmeter that measures: 8.2.1. Potential difference across the ends of a conductor. 8.2.2. Emf. 8.2.3. Terminal potential difference. Give a condition for the voltmeter to measure the terminal potential difference, with reference to the switch (S). (2) (1) (1) (2) 8.3 Calculate the amount of charge that passes through a point in a circuit when a current of 1,5 A flows for 2,5 minutes. (4) [10]​