Question

Standard cell of 1.1 V emf is balanced at 0.88 m length of the potentiometer wire. Potential difference across 1 Ω resistance is balanced at 0.20 m length of the wire of potentiometer. If the reading of ammeter is 0.20 A, then find out the error in the measurement of ammeter.

Answer 1

From principle of potentiometer,

Reading in ammeter (I) = 0.20 amp
Error in the measurement of current (ΔI) = I – I’
= 0.20 – 0.25 = -0.05 amp