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InterviewSolution
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Increasing the current sensitivity of a galvanometer may not necessarily increase its voltage sensitivity. Justify this statement. |
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Answer» Current sensitivity of a galvanometer is given by `I_s=(nBA)/(k)` where n is the no. of turns in the coil, A is the area of each turn of the coil, B is the strength of uniform magnetic field and k is the restoring torque per unit twist of suspension fibre in galvanometer. Voltage sensitivity `V_s=(I_s)/(R)=(nBA)/(kR)` `I_s` can be increased by increasing n and A. But increase of n increases the resistance R of galvanometer. Due to it, `V_s` will decrease. A can not be increased beyond a limit because in that case the entire coil will not be in a uniform magnetic field. Moreover it will make the galvanometer bulky and unmanageable. |
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