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'Resistance' printed from https://nrich.maths.org/
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When resistances are connected in a line so that the current in
the circuit has only one route to take the total resistance is the
sum of the separate resistances. The resistances are said to be
connected in series . In
this diagram the total resistance $R$ is given by $R = R_1 + R_2 +
R_3$. |
| When resistances are connected in parallel so that, at a junction,
the current flows along more than one route, the reciprocal of the
total resistance is the sum of the reciprocals of the separate
resistances. In this diagram the total resistance $R$ is given by
$${1 \over R} = {1 \over R_1} + {1 \over R_2} + {1 \over
R_3}.$$ |
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