Resistance. When a current ... resistance of the wire is. 1. ... In equations, if the resistivity of the ... bulb is connected in ... bulbs in parallel is half that ... An idealbattery is hooked to a light bulb ... power output from the ... the current is cut in half. If we include the effects of internal resistance in the battery, we expect the terminal voltage to be slightly ... it delivers is also cut in half. .... it as the one battery originally, which means each battery provides half of the power dissipated by the bulb.