question_answer

In the given circuit, a meter bridge is shown in balanced state. The resistance of bridge wire is\[1\,\Omega /cm\]. The current I drawn from the battery of negligible internal resistance is-

A) 0.22A               

B) 0.33A

C) 0.44A               

D) 0.66A

Correct Answer: D

Solution :

\[\frac{x}{6}=\frac{40}{60}=\frac{2}{3}\] \[x\,\,=\,\,4\,\Omega \] \[{{\operatorname{R}}_{eq}}\,\,=\,\,\frac{10\times 100}{10+100}\,\,=\,\,\frac{1000}{110}\,\,=\,\,\frac{100}{11}\] \[I\,\,=\,\,\frac{V}{{{\operatorname{R}}_{eq}}}\,\,=\,\,\frac{6}{100/11}\,\,=\,\,\frac{66}{100}\,\,=\,\,0.66\,A\]