Kirchhoff's laws and combining resistorsEdexcel International A Level Physics: Mind map

Exam questions on Kirchhoff's laws and combining resistors

1. A technician connects a 12 V battery of negligible internal resistance in series with a 4.0 Ω resistor and an 8.0 Ω resistor.
   Calculate the potential difference across each resistor and show that your values are consistent with conservation of energy.2 marks
2. A 6.0 Ω resistor and a 3.0 Ω resistor are connected in parallel across a 9.0 V battery of negligible internal resistance.
   Calculate the current in each resistor and show that the total current is consistent with conservation of charge.2 marks
3. A teacher wants to show that the equations for combining resistors can be derived from conservation laws. She considers two resistors, R₁ and R₂, connected to a supply of potential difference V. First they are connected in series, with total current I, and then in parallel, with total current I.
   Use conservation laws to derive the equation for the total resistance R of two resistors in series.3 marks