Question 361 of 380
A galvanometer having a resistance of and 30 division on both sides has figure of merit 0.005 ampere/ division. The resistance that should be connected in series such that it can be used as a voltmeter upto 15 volt, is:
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Answer: (C)
Deflection current
Where, Number of divisions and
division
$\begin{array}{l}
=15 \times 10^{-2}=0.15 \\
\mathrm{v}=\mathrm{I}_{\mathrm{g}}[20+\mathrm{R}] \\
15=0.15[20+\mathrm{R}] \\
100=20+\mathrm{R} \\
\mathrm{R}=80 \Omega
\end{array}$
Where, Number of divisions and
division
$\begin{array}{l}
=15 \times 10^{-2}=0.15 \\
\mathrm{v}=\mathrm{I}_{\mathrm{g}}[20+\mathrm{R}] \\
15=0.15[20+\mathrm{R}] \\
100=20+\mathrm{R} \\
\mathrm{R}=80 \Omega
\end{array}$