Question

A standard 50W electirc bulb in series with a room heater is connected across the mains. If the 50W bulb is replaced by `100W` bulb the heater output will
A. increase
B. decrease
C. remains same
D. no conclusion

Answer 1

Correct Answer - A

Resistance of bulb `R_(B) = (V^2)/(P)`
As `50W` is replaced by `100W`, resistance of bulb decreases, current supplied by battery increases, hence power consumed in helter increases.