A cell having a steady emf of 2 volt is connected across the potentiometer wire of length 10m. The potentiometer wire is of manganine and having of $11.5\Omega /m$. A new resistance of $5\Omega$ with negligible length is put in series with the potentiometer wire.

What is potential gradient when $5\Omega$ resistance is not connected.

0.2 V/m                                

Fall in potential per meter  =$\frac{\text{Applied Potential}}{\text{length of the wire}} $= $\frac{2}{10}$ = 0.2 V/m 

$\text{Potential Gradient} = 0.2V/m$