Question 632: Current Electricity

Question

Two metal wires of identical dimensions are connected in series. If $\sigma $
1
and $\sigma $
2
are the conductivity of the combination is

Accepted Answer

In figure, two metal wires of identical dimension are connected in series
${R_{eq}} = {1 \over {{\sigma _1}A}} + {1 \over {{\sigma _2}A}} = {{{l_{eq}}} \over {{\sigma _{eq}}{A_{eq}}}}$
${{2l} \over {{\sigma _{eq}}A}} = {1 \over A}\left( {{{{\sigma _1} + {\sigma _2}} \over {{\sigma _1}{\sigma _2}}}} ight)$
$ 	herefore {\sigma _{eq}} = {{2{\sigma _1}{\sigma _2}} \over {{\sigma _1} + {\sigma _2}}}$
![](https://neetcare-image.cdn.examgoal.net/1qpqahkk7u0rm10/0d06f511-9457-45a5-8651-28773b15c1a8/db507930-6745-11ea-aedc-f1c8d8e0194b/file-1qpqahkk7u0rm11-469w.jpg)

Answer

${{{\sigma _1} + {\sigma _2}} \over {{\sigma _1}{\sigma _2}}}$

Answer

${{{\sigma _1}{\sigma _2}} \over {{\sigma _1} + {\sigma _2}}}$

Answer

${{2{\sigma _1}{\sigma _2}} \over {{\sigma _1} + {\sigma _2}}}$

Answer

${{{\sigma _1} + {\sigma _2}} \over {2{\sigma _1}{\sigma _2}}}$

Current Electricity

Two metal wires of identical dimensions are connected in series. If \sigma 1 and \sigma 2 are the conductivity of the combination is

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