A) \[1\,\Omega \]
B) \[0.5\,\Omega \]
C) zero
D) \[2\,\Omega \]
E) \[1.5\,\Omega \]
Correct Answer: E
Solution :
Let n cells be in series and m in parallel, then \[\frac{nE}{R+nr}=\frac{E}{R+\frac{r}{m}}\] \[\Rightarrow \] \[n\left[ R+\frac{r}{m} \right]=R+nr\] \[\Rightarrow \] \[nRm+nr=Rm+mnr\] \[\Rightarrow \] \[6+2r=3+4r\] \[\Rightarrow \] \[2r=3\] \[\Rightarrow \] \[r=1.5\,\Omega \]You need to login to perform this action.
You will be redirected in
3 sec