A potentiometer wire has length 4 ~m and resistance 5 . It is connected in series with 495 resistance and a cell of e.m.f. 4 ~V . The potential gradient along the wire is

Step-by-step solution

Total resistance =495+5=500 current I= 4 500 =8 10⁻³ ~A P.D. across the wire = IR =8 10⁻³ 5=40 10⁻³ ~V aligned Potential gradient &= 40 10⁻³ 4 &=10⁻² ~V / m =0.01 ~V / m aligned