Question

A 2 volt battery, a $15\Omega$ resistor and a potentiometer of 100 cm length, all are connected in series. If the resistance of potentiometer wire is $5\Omega$, then the potential gradient of the potentiometer wire is

• A. 0.005 V/cm
• B. 0.05 V/cm
• C. 0.02 V/cm
• D. 0.2 V/cm

Answer 1

The correct option is A 0.005 V/cm

By using $x=\frac{e}{(R+R_h+r)}.\frac{R}{L}\Rightarrow x=\frac{2}{(5+15+0)}\times \frac{5}{1}=0.5V/m=0.005V/cm$