Series and parallel circuits and conservation lawsEdexcel A-Level Physics: Mind map

Exam questions on Series and parallel circuits and conservation laws

1. A string of decorative lights consists of 20 identical lamps connected in series to a 230 V supply.
   Explain, using conservation of energy, why the potential differences across the 20 lamps add up to the p.d. of the supply.2 marks
2. Two resistors, of resistance 6.0 Ω and 12 Ω, are connected in parallel across a 12 V battery that has negligible internal resistance.
   Explain why the combined resistance is less than the resistance of the 6.0 Ω resistor alone.2 marks
3. A circuit contains a 9.0 V battery of negligible internal resistance. A 15 Ω resistor is connected in series with a parallel combination of a 30 Ω resistor and a 60 Ω resistor.
   Calculate the total resistance of the circuit.3 marks