question_answer

Two lamps, one rated 60 W at 220 V and the other 40 W at 220 V, are connected in parallel to the electric supply at 220 V (a) Draw a circuit diagram to show the connections. (b) Calculate the current drawn from the electric supply. (c) Calculate the total energy consumed by the two lamps together when they operate for one hour.  

Answer:

(a) The circuit diagram to show the given connection is shown below                                                               (1) (b) Current drawn by 40 W lamp, Current drawn by 60 W lamp,  Total electric current drawn from the electric supply   (1) (c) Total energy consumed in one hour = 60 x 1 + 40 x 1 = 100 Wh = 0.1 kWh                                                        (1)