Q. A daniel cell is balanced at 125 cm length of a potentiometer wire. When the cell is circuited by a resistance of $2 \, \Omega$ , the balance length is obtained at 100 cm. The internal resistance of the Daniel cell is
NTA AbhyasNTA Abhyas 2022Current Electricity
Solution:
As we know that the internal resistance of Daniel cell is given as :-
$r=R\left(\frac{l_{l}}{l_{2}} - 1\right)$
$=2\left(\frac{125}{100} - 1\right)$
$=2\left(\frac{5}{4} - 1\right)$
$=2\times \frac{1}{4}$
$=0.5 \, \Omega$
$r=R\left(\frac{l_{l}}{l_{2}} - 1\right)$
$=2\left(\frac{125}{100} - 1\right)$
$=2\left(\frac{5}{4} - 1\right)$
$=2\times \frac{1}{4}$
$=0.5 \, \Omega$