NEET-XII-Physics
36: Permanent Magnets
- #12If the current is doubled, the deflection is also doubled in
(a) a tangent galvanometer
(b) a moving-coil galvanometer
(c) both
(d) nonedigAnsr: bAns : (b) a moving coil galvanometer
The current and deflection dependence of a moving coil galvanometer is given by
`` i=\frac{k}{nAB}\theta \Rightarrow i\propto \theta ``
Therefore, if we double the current, the deflection also gets doubled.
However, in a tangent galvanometer, `` i\propto \,\mathrm{\,tan\,}\theta ``; that is, there is no direct relation between `` \theta `` and current.
Hence, the correct option is
(b).
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