For designing a voltmeter of range \(50\,V\) and an ammeter of range \(10\,mA\) using a galvanometer which has a coil of resistance \(54\,\Omega\) showing a full scale deflection for \(1\,mA\) as in figure. \((A)\) for voltmeter \(R \approx 50\,k\Omega\) \((B)\) for ammeter \(r \approx 0.2\,\Omega\) \((C)\) for ammeter \(r \approx 6\,\Omega\) \((D)\) for voltmeter \(R \approx 5\,k \Omega\) \((E)\) for voltmeter \(R \approx 500 \Omega\) Choose the correct answer from the options given below

Pick an option to check your answer.

Verified Solution

Answer & Solution

Correct Answer

(C) \((A)\) and \((C)\)

Detailed explanation

For voltmeter

\(R =\frac{ V }{ I _{ g }}- G\)

\(=\frac{50}{10^{-3}}-54 \approx 50\,k \Omega\)

For ammeter

\(S=\frac{I_g G}{I-I_g}=\frac{10^{-3} \times 54}{(10-1) \times 10^{-3}}=6 \Omega( C )\)

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