Explain with diagrams what is meant by the “series combination” and “parallel combination” of resistances. In which case the resultant resistance is :
(i) less, and
(ii) more, than either of the individual resistances?
(i) Series combination
When two or more resistance are connected end to end consecutively, they are said to be connected in series combination. The combined resistance of any number of resistances connected in series in equal to the sum of the individual resistances.
R = R1 + R2 + .....
The resultant resistance is more than either of the individual resistances.
(ii) Parallel combination
When two or more resistances are connected between the same two point they are said to be connected in parallel combination. The reciprocal of the combined resistance of a number of resistances connected in parallel is equal to the sum of the reciprocals of all the individual resistances.
\(\frac{1}{R}\) = \(\frac{1}{R_1}\) + \(\frac{1}{R_2}\)
The resultant resistance less than either of the individual resistances.