The wiring of a house has resistance 6  Ω. A 100 W bulb is glowing. If a geyser of 1000 W is switched on, the change in potential drop across the bulb is nearly (Supply voltage is 220 V)

RBulb = 2202100 = 48.4  Ω(i) When only bulb is ON,  VBulb = 220 × 484490 = 217.4 V(ii) When geyser is also switched ON, equivalent resistance of bulb and geyser is R = 484 × 48.4484+48.4 = 44  ΩVoltage across the bulb, VBulb = 220 × 4450 = 193.6 VHence, the potential drop is 217.4−193.6=23.8  V