Question

A Daniel cell is balanced on 125 length of a potentiometer wire. Now the cell is short-circuited by a resistance 2 ohm and the balance is obtained at 100. The internal resistance of the Daniel cell is

• A. 0.5 ohm
• B. 1.5 ohm
• C. 1.25 ohm
• D. 4/5 ohm

Answer 1

Answer: (A)

0.5 ohm

Answer 2

$r = \left( \frac { l _ { 1 } - l _ { 2 } } { l _ { 2 } } \right) R = \left( \frac { 25 } { 100 } \right) 2 = 0.5 \Omega$