A) \[\sqrt{{{r}_{1}}{{r}_{2}}}\]
B) \[{{r}_{1}}+{{r}_{2}}\]
C) \[{{r}_{1}}-{{r}_{2}}\]
D) \[\frac{{{r}_{1}}+{{r}_{2}}}{2}\]
Correct Answer: C
Solution :
The figure is drawn accordingly. Potential across \[{{r}_{1}}\] is given by as \[{{V}_{1}}=E-i{{r}_{1}}\] ?(i) Similarly, potential across \[{{r}_{2}}\] is given by as \[{{V}_{2}}=E-i{{r}_{2}}\] ?(ii) For \[{{V}_{1}}\]to be zero. \[E-i{{r}_{1}}=0\,\]or \[E=i{{r}_{1}}\] Now, Eq. (ii) on by putting values \[E=i\,{{r}_{1}},\]becomes \[{{V}_{2}}=i{{r}_{1}}-i{{r}_{2}}=i({{r}_{1}}-{{r}_{2}})\] Total potential, \[V={{V}_{1}}+{{V}_{2}}={{V}_{2}}\] Hence, \[i\,R=i({{r}_{1}}-{{r}_{2}})\] So, \[R={{r}_{1}}-{{r}_{2}}\]You need to login to perform this action.
You will be redirected in
3 sec