Question

A potentiometer wire has length 10 metre and resistance 20 ohms. A 2.5 volt battery of negligible internal resistance is connected across the wire with an 80 ohms series resistance. The potential gradient on the wire will be​

Answer 1

Answer:

0.05 v/m

Explanation:

Given A potentiometer wire has length 10 metre and resistance 20 ohms. A 2.5 volt battery of negligible internal resistance is connected across the wire with an 80 ohms series resistance. The potential gradient on the wire will be

Given length of wire = 10 m, Resistance = 20 ohm, emf of battery = 2.5 v, resistance connected across wire = 80 ohm

We know that v = I R

So current Ip = emf / Rp + Rs + r

Ip = 2.5 / 20 + 80 (negligible internal resistance)

   = 1/40 A

We know that  

Potential gradient = Ip x Rp / L

                          = 1/40 x 20 / 10

                         = 1/20

                           = 0.05 v/m

So potential gradient on the wire will be 0.05 v/m