Circuits - series and parallel
Q6. X and Y are two lamps. X is rated at 12V 36W and Y at 4.5V 2.0W.
(a) Calculate the current in each lamp when it is operated at its correct working voltage.
(2 marks)
(b) The two lamps are connected into the circuit as shown in the diagram below.
The battery has an emf of 24V and negligible internal resistance. The resistors, R1 and R2 are chosen so that the lamps are operating at their correct working voltage.
(i) Calculate the pd across R1.
(ii) Calculate the current in R1.
(iii) Calculate the resistance of R1.
(iv) Calculate the pd across R2.
(v) Calculate the resistance of R2.
(5 marks)
(c) The filament of the lamp in X breaks and the lamp no longer conducts. It is observed that the voltmeter reading decreases and lamp Y glows more brightly.
(i) Explain without calculation why the voltmeter reading decreases.
(2 marks)
(ii) Explain without calculation why the lamp Y glows more brightly.
(2 marks)
(Total 11 marks)
About this site
