hey thankz
i think i got it now.all this time i was thinking the internal and the external resistance are in parallel.but in fact they are in series.
so if you have 1 V source and internal resistance of 1ohms and you connect it to a external resistance of 2 ohms.
then the current flowing through it is i=v/r i=1/(1+2)
which is 0.3 A but the voltage across the external resistance is
V=IR V=0.3*2
which is 0.6 V
this is what you mean right. well this makes sense now
that's the idea
but one more small question can you tell me in simple terms how does a internal resistance can limit the maximum current that can be provided by a voltage source. i mean if the internal resistance is 1 ohm and voltage is 1 V the maximum current it can produce is 1 A right. but in books i have seen that they have said the internal resistance is for a 1.5 V battery is about 1 ohm and yet the maximum current it can provide is around 250mA how can this be.