Define current sensitivity and voltage sensitivity of a galvanometer. Justify the statement that increasing the current sensitivity may not necessarily increase the voltage sensitivity of a galvanometer.
Solution
\textbf{Current sensitivity} is the deflection per unit current, . \textbf{Voltage sensitivity} is the deflection per unit voltage, , where is the coil resistance. If current sensitivity is doubled by doubling the number of turns , the length of wire and hence the resistance also roughly doubles. Since voltage sensitivity , the two increases cancel and the voltage sensitivity need not rise.
CBSE Class 12 Board · 2009 · Subjective