When a Daniel cell is connected in the secondary circuit of a potentiometer, the balancing length is found to be 540 cm. If the balancing length becomes 500 cm. When the cell is short-circuited with 1Omega, the internal resistance of the cell is

Options

A. `0.08Omega`
B. `0.04Omega`
C. `1.0Omega`
D. `1.08Omega`

Answer

A

Explanation

Internal resistance ,
`r=R((l_(1)-l_(2))/(l_(2)))=1((540-500)/(500))=(40)/(500)=0.08Omega`