In an experiment a resistor is connected across a variable power supply. The following observations are taken:
• When the voltmeter reads 2.8V, the ammeter shows 0.20A.
• The applied voltage is then increased until the voltmeter reads 7.0V.
(i) Calculate the resistance of the resistor from the first set of readings.
(ii) Assuming the resistance remains constant, predict the current that should be observed on the ammeter when the voltage is 7.0V.
(iii) How much electrical energy, in joules, is converted to heat in the resistor in 5min at the current calculated in part (ii)? (Take 1min=60s.)