Question

The brightness of light emitted by a bulb is observed to decrease when an electric heater is connected in series with it .Suggest the likely reason for this observation

Answer 1

The voltage is divided into two parts so the available voltage for the bulb is less than 220 V. So, the brightness of light emitted from the bulb will decrease. The reason for this is that heater demands higher voltage so some of the voltage will be cut off from the bulb in order to provide full current to the heater because heater needs more current to work as compared to the bulb.