JEE Main Online Paper ( Held On 25 April 2013 )
A) P and R
B) P and Q
C) Q and R
D) Any two points
Correct Answer: B
Solution :
Resistance between P and Q \[{{r}_{PQ}}={{r}_{11}}\left( \frac{r}{3}+\frac{r}{2} \right)=\frac{r\times \frac{5}{6}r}{r+\frac{5}{6}r}=\frac{5}{11}r\] Resistance between Q and R \[{{r}_{QR}}=\frac{r}{2}11(r+\frac{r}{3})=\frac{\frac{r}{2}\times \frac{4}{3}r}{\frac{r}{2}+\frac{4}{3}r}=\frac{4}{11}r\] Resistance between P and R \[{{r}_{PR}}=\frac{r}{3}11\left( \frac{r}{2}+r \right)=\frac{\frac{r}{3}\times \frac{3}{2}r}{\frac{r}{3}+\frac{3}{2}r}=\frac{3}{11}r\] Hence, it is clear that \[{{r}_{PQ}}\]is maximum
You need to login to perform this action.
You will be redirected in
3 sec
