dtdV=cm1mV
For a potentiometer 1cm of wire has 1mV of voltage
So,
400cm has 0.4V.
Given R must be connected in series
ΔV=0.4=8+R2×8
8+R=0.416=4160=40
⇒R=32Ω
A potentiometer wire has length 4 m and resistance 8Ω . The resistance that must be connected in series with the wire and an accumulator of e.m.f. 2V , so as to get a potential gradient 1 mV per cm on the wire is :
Held on 30 Apr 2015 · Verified 9 Jul 2026.
32Ω
40Ω
44Ω
48Ω
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