A room is supplied through a pair of parallel branches
MATHEMATICS · Multi-part · ISC · Physics · Current Electricity · Electrical energy and power
Problem
A room is supplied through a pair of parallel branches, each branch protected by its own fuse of rating 5A. Branch A feeds two lamps, each 100W,220V, while Branch B feeds a room-cooler rated 400W,220V. A visitor wants to add an electric iron rated 880W,220V to Branch A.
(i) Calculate the current in each branch before the iron is added.
(ii) If the iron is connected to Branch A, determine the new current in that branch and state whether its fuse will blow. Show your calculations clearly.
(iii) Suggest one safe electrical modification that would allow all four appliances to be used simultaneously and justify your suggestion with suitable calculations.
(iv) Using the data above, quantitatively show why connecting all four appliances in series to the mains would be impractical.