(a) State the relationship between impedence, voltage and current. (6)

(b) The filament of a 230V lamp takes a current of 0.261A when working at its normal temprature of 2000°C. The temperature coefficient of the tungsten filament material can be taken as 0.005 Ohms/Ohms at 0° C/C. Find the approximate current which flows at the instant of switching on the supply of the cold lamp, which can be considered to be at a room temperature of 20°C (10)