Multiplying Power of a Shunt

When a resistance is placed in parallel with a galvanometer on a circuit the following relation obtains. Let s and g equal the resistances of the shunt and galvanometer respectively, S and G the currents in amperes passing through them, V the potential difference between their common terminals, and A the whole current in amperes. Then we have   A = ( (s + g ) / s ) * G and ( (s + g ) / s ) is termed the multiplying power of the shunt, as it is the factor by which the current passing through the galvanometer must be multiplied by to produce the total current.