A bread toaster is designed for 1150 W at 230 V and has a wire element of fixed resistance.
Domestic voltage, however, can vary between ±10% of its nominal value.
(i) Determine the resistance of the toaster element from its name-plate rating.
(ii) Calculate the current through the toaster when the supply voltage rises to 253 V (+10%).
(iii) Cartridge fuses of 5 A and 10 A are available. Select the smallest rating that will neither blow under the highest expected operating current (from part (ii)) nor allow dangerous over-currents to persist in case of a short-circuit drawing 25 A.
(iv) Give one reason, based on your calculations, why the other fuse rating is unsuitable.