An incandescent lamp is rated 120V,60W but is to be operated from a 240V mains supply by connecting a series resistor with it.
(i) Calculate the resistance of the lamp when it glows at its rated conditions.
(ii) Determine the resistance that must be connected in series so that the lamp still receives 120V when plugged into the 240V mains.
(iii) Find the power dissipated in the series resistor when the circuit is working as intended.
(iv) Comment, with calculation, on the fraction of the total power supplied by the mains that actually reaches the lamp.