Match List I with List IIList IList IIA.Ammeter is madeI.By connectin…

The correct answer is Option (4) → A-IV, B-I, C-II, D-III

A moving coil galvanometer is converted into an ammeter or a voltmeter by adding a suitable resistance, and its sensitivity depends on the field and the torque on the coil.

(A) Ammeter is made — this matches (IV) By connecting a low resistance in parallel with moving coil Galvanometer. The low shunt carries most of the current, so the ammeter has a very small total resistance.

(B) Voltmeter is made — this matches (I) By connecting a high resistance in series with moving coil Galvanometer. The high series resistance makes the voltmeter draw very little current.

(C) Soft iron core in moving coil galvanometer — this matches (II) Increases the strength of magnetic field. Soft iron has a high permeability, so it concentrates the field lines through the coil.

(D) Radial field in moving coil galvanometer — this matches (III) Increases torque produced in coil. In a radial field the plane of the coil always lies along the field, so the torque \( NIAB\sin\theta \) has its maximum value \( NIAB \) at every position.

NCERT (2026-27):
The Moving Coil Galvanometer – “… There is a cylindrical soft iron core which not only makes the field radial but also increases the strength of the magnetic field. When a current flows through the coil, a torque acts on it. This torque is given by Eq. (4.20) to be

    \( \displaystyle \tau = NIAB \)”

The Moving Coil Galvanometer – “… To overcome these difficulties, one attaches a small resistance r_s, called shunt resistance, in parallel with the galvanometer coil; so that most of the current passes through the shunt.”

The Moving Coil Galvanometer – “… To ensure this, a large resistance R is connected in series with the galvanometer.”