2024 Re-NEET Current ElectricityMeter bridge / Wheatstone bridge balance condition Medium Question 16 of 130 in Current Electricity

The given circuit shows a uniform straight wire AB of 40 cm length fixed at both ends. In order to get zero reading in the galvanometer G, the free end of J is to be placed from B at:

A 32 cm
B 8 cm
C 16 cm
D 24 cm

The answer is D.

Solution

Using the meter bridge balance condition with resistances $8\ \Omega$ and $12\ \Omega$: $\dfrac{8}{\ell}=\dfrac{12}{40-\ell}\Rightarrow 8(40-\ell)=12\ell\Rightarrow320=20\ell\Rightarrow\ell=16$ cm from A. So the distance from B is $40-16=24$ cm.

Concept Meter bridge / Wheatstone bridge balance condition

Current Electricity in past papers

130 questions from this chapter have appeared across 27 exam years.