In the opposite circuit, a voltmeter V is connected in parallel with the headlights of an automobile of resistance Rp and an ammeter A indicates the intensity of the current passing through them. The internal resistance of the starter is Rd and that of the battery is r=0.05 . By turning on the headlights, the voltmeter registers a difference of potential of 12V and the ammeter a current of 20A. Then starting the car, the headlights dim a little and the current drops to 15A. Determine : a) The resistance Rp of the headlights. b) The F.e.m.. c) The current flowing in the starter when starting with the headlights on. d) The potential difference indicated by the voltmeter during start-up. e) The internal resistance Rd of the starter