Question

this is my question physics .. the current electricity

Answer 1

At the middle of potentiometer wire, we can divide it into two resistances each of resistance R°/2 since potentiometer wire is uniform.

So, we can write equivalent resistance of left half (as in diagram) as 1/Req=1/R + 1/(R°/2)

Req=R×R°/(R°+2R)

Let current i be flowing through the circuit,

Potential difference across left half=i×Req

Across right half, potential difference is i×R°/2

By Kirchoff's voltage law,

V-i×Req-i×R°/2=0 -(1)

According to the question, we need to find i×Req

From (1),

i×Req=V-i×R°/2 -(2)

i=V/(Req+R°/2)... by ohm's law

Substitute this in (2).