A room-heater is designed to operate at 220 V with a power rating of 1.0 kW. Owing to manufacturing tolerances the resistance of the heating element can deviate by ±5% from its nominal value. Assume the element behaves as an ohmic conductor over the relevant temperature range.
(i) Calculate the nominal resistance of the heating element corresponding to the stated rating.
(ii) Determine the maximum and minimum possible resistance values of the element arising from the ±5% tolerance.
(iii) For each of these extreme resistance values, compute the power that would be dissipated when the heater is connected to a 220 V supply.
(iv) Discuss whether either of these power values could pose a risk of exceeding the designed thermal limits of the appliance.