Search any question & find its solution
Question:
Answered & Verified by Expert
A galvanometer coil has a resistance of \( 50 \Omega \) and the meter shows full scale deflection for a
current of \( 5 \mathrm{~mA} \), This galvanometer is converted into voltmeter of range \( 0-20 \mathrm{~V} \) by connecting
Options:
current of \( 5 \mathrm{~mA} \), This galvanometer is converted into voltmeter of range \( 0-20 \mathrm{~V} \) by connecting
Solution:
1227 Upvotes
Verified Answer
The correct answer is:
\( 3950 \Omega \) in series with galvanometer
We know, \( R=\frac{V}{I_{g}}-G \)
Given,
\[
\begin{array}{l}
V=20 \mathrm{~V} ; I_{g}=5 \mathrm{~mA}=5 \times 10^{-3} \mathrm{~A} ; G=50 \Omega \\
\Rightarrow R=\frac{20}{5 \times 10^{-3}}-50=\frac{20}{0.005}-50=3950 \Omega
\end{array}
\]
Therefore, the given galvanometer is converted into voltmeter of range \( 0-20 \mathrm{~V} \) by connecting \( 3950 \Omega \) in series with
galvanometer.
Given,
\[
\begin{array}{l}
V=20 \mathrm{~V} ; I_{g}=5 \mathrm{~mA}=5 \times 10^{-3} \mathrm{~A} ; G=50 \Omega \\
\Rightarrow R=\frac{20}{5 \times 10^{-3}}-50=\frac{20}{0.005}-50=3950 \Omega
\end{array}
\]
Therefore, the given galvanometer is converted into voltmeter of range \( 0-20 \mathrm{~V} \) by connecting \( 3950 \Omega \) in series with
galvanometer.
Looking for more such questions to practice?
Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.