internal resistance
What would happen to the brightness of the other two bulbs if bulb A were to burn out in a simple circuit containing a battery of negligible internal resistance and three identical light bulbs where Bulb A is wired in parallel with Bulb B and this combination is wired in series with Bulb C?
[1] only bulb B would get brighter.
[2] both would get brighter.
[3] bulb B would get brighter and bulb C would get dimmer.
[4] bulb B would get dimmer and bulb C would get brighter.
[5] There would be no change in the brightness of either bulb B or bulb C.
