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1)according to kirchoff's first law ,,total current enteringto a junction =total current leaving,,

and in second law............

sigmaiR =sigmaE,,,,,,,,,,,,,[E=e.m.f. sources]

1)there r some rules,,,,if we move in a circuit ,in the direction of current i, iR is negative and if opposite to current i,iR is positive,,,

2)now for e.m.f. sources,,,if we move from negative terminal to positive terminal then  e.m.f. is taken as negative and from and on moving positive terminal to negative terminal e.m.f. is taken as positive.

3)kirchoff's law is based on conservation of energy or electric field.

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