Current sensitivity : It is defined as the deflection of coil per unit current flowing in it.
Current Sensitivity,
Voltage sensitivity : It is defined on the deflection of coil per unit potential difference across its ends.
Voltage Sensitivty,
where G is resistance of galvanometer.
Justification: When number of turns N is doubled, then the current sensitivity (∝ N) is doubled; but at the same time, the resistance of galvanometer coil (G) will also be doubled, so voltage sensitivity ( Sv ∝u200b N/G) will remain unchanged; hence inreasing current sensitivity does not necessarily increase the voltage sensitivity.
