Self Test on Tutorial 7 Try these questions on file paper.  Then mark them with the model answers. The diagram shows a series circuit. (a) What is the total resistance?                                                                          (2)             (b) What is the current in the circuit?                                                                   (2)             (c) What is the potential difference across the 50 ohm resistor?                            (2)   This circuit is a parallel circuit. (a) What is the total resistance?                                                                               (3)             (b) What is the current in the circuit?                                                                        (2)             (c) What is the potential difference across the 50 ohm resistor?                                (1)             (d) What is the current through the 30 ohm resistor?                                                 (2)   3.         (a)  What is Kirchhoff’s First Law?  Draw a diagram to illustrate your answer.         (2)                                                                                                   (b)    Write Kirchhoff’s Second Law.  Draw a diagram that explains this                   (3) (c)      Explain how these two laws are used.                                                               (2)   4.     Look at the circuit below: (a) What is the total resistance?                                                                          (4)             (b) What is the current in the circuit?                                                                   (1)             (c) What is the potential difference across the 30 ohm resistor?                            (2)             (d) What is the current through the 40 ohm resistor?                                             (2)                                                                                                             Total = 30 marks