The resistance of a 10 m long potentiometer wire is 20 `Omega` . It is connected in series with a 3 V battery and 10 `Omega` resistor. The potential difference between two points separated by distance 30 cm is equal to .......

Options

A. 0.02 V
B. 0.06 V
C. 0.1 V
D. 1.2 V

Answer

B

Explanation

0.06 V
`L rho = 20 Omega , L = 10 ` m
`therefore rho - 2 (Omega)/(m)`
Now, `V_(l) = I rho` l
`therefore I =(E rho l )/(I rho + R + r) = (3 xx 2 xx 0.3)/(20 + 10 + 0) = (1.8)/(30)`
`therefore V_(l) = 0.06 ` V