b (1) to give (1) to give        3.3 (1) (3 marks) R  Ω c (1) to give (1) to give 3 (1) (3 marks)      R Ω 3 Resistance of parallel network is 30 (1), total resistance in circuit is 60 (1), Ω Ω use of (1) gives a value of 0.2 A (1) (4 marks) I  I   4 Use of (1) shows that the effective resistance of the circuit is  R V I 12 V 0.1 A 120 (1), so this means that becomes (1), so       R Ω (1) so 600 (1) (5   marks) Rlamp − Ω 5 a Resistance of parallel network 10 (1) plus the 20 resistor in series  Ω Ω becomes 30 (1). (2 marks) Ω b Current leaving cell is given by (1) 0.4 A (1) so current through I    bulb A is 0.4 A (1), through bulb B is 0.2 A (1) and through bulb C it is 0.2 A marks) c When switch opened, circuit resistance increases (1) to 40 (1) so current Ω decreases (1) to 0.3 A (1). (4 marks)
b    (1) to give     (1) to give R  3.3 Ω (1) (3 marks) c   (1) to give   (1) to give R  3 Ω (1) (3 marks) 3 Resistance of parallel network is 30 Ω (1), total resistance in circuit is 60 Ω (1), use of I  (1) gives a value of I   0.2 A (1) (4 marks) 4 Use of R  V I (1) shows that the effective resistance of the circuit is R  12 V 0.1 A  120 Ω (1), so this means that   becomes   (1), so  − (1) so Rlamp  600 Ω (1) (5 marks) 5 a Resistance of parallel network  10 Ω (1) plus the 20 Ω resistor in series becomes 30 Ω (1). (2 marks) b Current leaving cell is given by I  (1)   0.4 A (1) so current through bulb A is 0.4 A (1), through bulb B is 0.2 A (1) and through bulb C it is 0.2 A marks) c When switch opened, circuit resistance increases (1) to 40 Ω (1) so current decreases (1) to 0.3 A (1). (4 marks)
oxo_AQA16_P406_bt01_xxaann.docx