This section is about applying some more advanced rules to circuits that build on your GCSE skills. The trick is to realise that you must be 100% logical and treat it as a mathematical exercise. If you set up the problems correctly then you cannot go wrong. Take note of these things that you must be able to do…

- Make sure you treat current and pd as having a direction.
- Learn how to apply reciprocal equations for 1/R for resistors in parallel
- Learn what the gradient and intercept mean on an Internal Resistance circuit graph
- Remember that a power source is a “real source” and will get warm so lose energy! A 3V cell does not output 3V!
- When thinking about potential dividers the trick is to realise that current is the same through each resistor. So setup two equations for V for each then I is the same for both!

13 DC Circuits (Main PPT Updated!)

13 DC Circuits Student Booklet (student booklet notes + PPT selected slides)

Donkey_Model (Think about how a model might help you?)

**13.1 Circuit rules**

5_1_kirchoffs laws (problem sheet)

**13.2 More about resistance**

5_2_Practical_investigating_resistors (Practical on Resistors)

5_2_practical_cons_energy (Practical sheet proving Kirchhoff’s laws)

resistor_cube_problem (Extension – 3D resistor cube problem – for fun!)

**13.3 Emf and internal resistance**

Internal Resistance Calculator (Hyper Physics)

5_3_EHT_Practical_Demo (teacher demo with results to graph)

5_3_Internal_Resistance Problems (problems sheet)

5_3_IR_of_Battery variable current method (practical method 1)

5_3_IR_of_Cell adding bulbs method (practical method 2) Results 3 Cells (excel results)

5_3_IR_Practical_Higher_Ability

5_3_IOP_notes (extra reading from IOP)

**13.4 More circuit calculations**

5_4_Investigation_cell_combinations (Crucial practical which explores how PD behaves for series & parallel)

**13.5 The potential divider**

5_4_Potential_Dividers Worksheet

**Youtube Video Tutorials “Electricity” – Steve4Physics****E10 Kirchhoff’s First Law****E11 Kirchhoff’s Second Law****E12 Resistors in series****E13 Resistors in parallel****E14 The resistance of series and parallel resistor combinations****E15 Internal Resistance 1 of 4****E16 Internal Resistance 2 of 4****E17 Internal Resistance 3 of 4****E18 Internal Resistance 4 of 4****E19 Potential (Voltage) Dividers****E20 Potentiometers****E21 Power in Electrical Circuits – Part 1 of 2****E22 Power in Electrical Circuits – Part 2 of 2****E25 Resistance and Temperature 1 of 3****E26 Resistance and Temperature 2 of 3. Semiconductors****E27 Resistance and Temperature 3 of 3 Superconductors****E28 Circuits – Problem Solving**