A) 27\[\Omega \]
B) 90 \[\Omega \]
C) 4\[\Omega \]
D) 7.5 \[\Omega \]
Correct Answer: D
Solution :
Resistance\[R\propto \frac{1}{{{r}^{2}}}\] \[\frac{{{R}_{1}}}{{{R}_{2}}}={{\left( \frac{{{r}_{2}}}{{{r}_{1}}} \right)}^{2}}\Rightarrow \frac{5}{{{R}_{2}}}={{\left( \frac{3}{9} \right)}^{2}}\] \[{{R}_{2}}=5\times {{(3)}^{2}}=5\times 9=45\,\Omega \] The equivalent resistance of 6 wires of resistance\[{{R}_{2}}\]each connected in parallel order \[=\frac{{{R}_{2}}}{6}=\frac{45}{6}=7.5\,\,\Omega \]You need to login to perform this action.
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