If a third bulb is added in parallel to circuit (A), how would the brightness of each of the other
bulbs change? Why?If a third bulb is added in parallel to circuit, how would the brightness of each of the other bulbs change?thank you anonymous student for helping me finish all my honors points :)If a third bulb is added in parallel to circuit, how would the brightness of each of the other bulbs change?Since the third bulb is added in parallel, the impressed voltage across the existing bulbs would not change. Thus the existing bulbs would draw the same current as before and their brightness would remain the same.If a third bulb is added in parallel to circuit, how would the brightness of each of the other bulbs change?the existing bulbs would get dimmer.
However, this is a math question. In real life, a bulb that's lit has higher resistance than a bulb that's not. IE, heating the filament changes the resistance. What that means is that the calculations are a bit off in real life, because the resistance changes when the bulb is dimmer. However, for our purposes, we'll ignore that, and just to the calculation.
let's assume that they're 110 watt bulbs, so that normally they draw 1 amp.
and their resistance is r=v/i = 110/1 = 110 ohms
when you put 2 in series, then you have 220 ohms, so you only get i=v/r = 110/220 = 0.5 amps.
less amps = dimmer bulb.
when you then put 3 bulbs in series, you get i=v/r = 110/330 = 0.333 amps.
even less amps = even dimmer bulb.
also, with 2 bulbs, of equal resistance are in series, the voltage drop across each one would be 55, so the power would be 55*0.5 = 22.5 watts, rather than the 100 for which the bulb was designed, so it would be far less than 1/2 as bright.
with 3 bulbs, the voltage drop across each would be 110/3 = 37 and the power would be 37*0.333 = 12.32 watts -- again, a serious step down, probably enough that you'd not get the bulb to even light.
