Answer Happy

The headlamp and two IDENTICAL tail lamps of a scooter are connected in parallel to a battery with unknown internal resistance as shown in the simplified circuit diagram below. The headlamp has a resistance of 2,4 0 and is controlled by switch S₁. The tail lamps are controlled by switch S₂. The resistance of the connecting wires may be ignored. The graph alongside shows the potential difference across the terminals of the battery before and after switch S₁ is closed (whilst switch S₂ is open). Switch S₁ is closed at time t₁. 2,40 time (s) 10.1 10.2 10.3 10.4 potential difference (volts) 12 9,6 tail lamp 1 tail lamp 2 Use the graph to determine the emf of the battery. (1) WITH ONLY SWITCH S₁ CLOSED, calculate the following: 10.2.1 Current through the headlamp (3) 10.2.2 Internal resistance, r, of the battery (3) BOTH SWITCHES S₁ AND S₂ ARE NOW CLOSED. The battery delivers a current of 6 A during this period. Calculate the resistance of each tail lamp. (5) How will the reading on the voltmeter be affected if the headlamp burns out? (Both switches S₁ and S₂ are still closed.) Write down only INCREASES, DECREASES or REMAINS THE SAME. Give an explanation. (3) [15]