A ceiling fan is rated "100 W, 220 V". To reduce its speed, a variable resistor (rheostat) is to be connected in series with the fan across a 220V supply so that the fan now consumes only 60W. Assume that the resistance of the fan does not change with temperature.
(a) Calculate the resistance of the fan from its rating.
(b) Determine the current that must flow through the fan for it to consume 60W.
(c) Find the resistance value that should be introduced in series so that the current obtained in part (b) flows when the combination is connected to the 220V supply.
(d) Compute the power dissipated in the rheostat at this setting.