Three bulbs are marked 25 W – 220 V, 60 W – 220 V and 100 W – 220 V. They are connected in series through a switch to a 220 V supply.
(a) Calculate the resistance of each bulb at its rated voltage.
(b) Determine the total current flowing in the circuit and the power actually consumed by each bulb in this series arrangement.
(c) Which of the three bulbs glows the brightest? Justify with numerical values.
(d) If the filament of the 25 W bulb breaks and the circuit becomes open, explain quantitatively what happens to the brightness and power consumption of the remaining two bulbs.
(e) Suppose instead the three bulbs were connected in parallel and the 25 W bulb filament breaks. Explain what would then happen to the brightness of the other two bulbs and to the total power drawn from the supply.