Q. A Daniel cell is balanced on $125cm$ length of a potentiometer wire. Now the cell is short-circuited by a resistance $2\ ohm$ and the balance is obtained at $100\ cm.$ The internal resistance of the Daniel cell is
A) $0.5\ ohm$
B) $1.5\ ohm$
C) $1.25\ ohm$
D) $4/5\ ohm$
Explanation
(a) $r = \left( \frac{l_{1} - l_{2}}{l_{2}} \right)R = \left( \frac{25}{100} \right)2 = 0.5\ \Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.