Four cells each of internal resistance 1 ohm and e.m.f. 1.9v are connected to a external resistance of 18 ohm.the cells are connected in pair of two. the two pairs are connected in parallel . find the terminal potential difference of this combination?

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Answer 1 · 2017-08-24T15:06:10

The potential difference is #=3.69V#

We apply the equation

#U=RI#

#E-U=rI#

#E=(R+r)I#

The emf is #E=2*1.9=3.8V#

The cells are in series-parallel and the internal resistances as well.

The total resistance is

#r+R=(1/2+1/2)+18=19Omega#

The current is

#I=3.9/19=0.21A#

So, the potential difference is

#=U=18*0.21=3.69V#