Question 3 [Marks 14] (i) Two light bulbs of resistance R_(A)=1Ω and R_(B)=5Ω are connected (a) in parallel and (b) in series. Derive the expression of power dissipation and show which one will glow brighter in either configuration, taking the power source to be ε(V). [4] (ii) State Kirchhoff's rules for electrical circuit analysis. [2] (iii) In the following circuit there are two power sources V_(1),V_(2) and three resistors R_(1),R_(2) and R_(3). The directions of currents I_(1),I_(2) and I_(3) are considered initially in order to solve this circuit. (a) Apply Kirchhoff's rules to determine an expression for I_(3) in terms of V_(1),V_(2) and three resistors R_(1),R_(2) and R_(3) only. [4] (b) Determine the sign and the values of I_(1),I_(2) and I_(3) for V=10V, V=3V; R_(1)=5Ω, R_(2)=10Ω and R_(3)=15Ω. [4]