Question

For the given potentiometer circuits , potential gradient is $0.025V/m$ and the ammeter reading is $0.1$ A. Now, when terminals $1$ and $2$ are connected balance point is obtained at $40cm$. Also when terminals $1$ and $3$ are connected balance point in obtained at $100cm$. If $3R=kX$, then the value of k will be

Answer 1

$R=\frac{v}{1}=\frac{1}{0.1}=10$
p.d across R in series with x=$0.025\times 100$
$=2.5v$
P.d across $\times =$(p.d across both-pd across R)
P.d across $\times =(2.5-1.0)=1.5$
current $\times =0.1A$
So $x=\frac{v}{1}=\frac{1.5}{0.1}=15$