question_answer 33)

An electric lamp of  a toaster of resistance , and a water filter of resistance , are connected  in parallel to a 220 V source. What is the resistance of an electric iron connected to the same source that takes as much current as all three appliances and what is the current through it?

Answer:

                 Resistance of the electric lamp,                  resistance of toaster,                  resistance of water filter,                  Since  and  are connected in parallel, their equivalent resistance  is given by                    r            Current through the three appliances, i.e.,     Since the electric iron connected to the same source (i.e., 220 V), takes as much current as all three appliance, i.e.,  its resistance is equal to i.e.,