A moving coil of galvanometer when shunted with \(2~\Omega\) resistance gives a full scale deflection for a current of \(500~\text{mA}\). When a resistance of \(470~\Omega\) is connected in series it gives a full scale deflection for \(10~\text{V}\) potential applied on it. The value of resistance of galvanometer coil is: (in \(\Omega\))
1. \(50\)
2. \(30\)
3. \(70\)
4. \(100\)
Subtopic:  Conversion to Ammeter & Voltmeter |
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A voltmeter with internal resistance of \(x~\Omega\) can used to measure upto \(20~\text{V}\). In order to increase its measuring range to \(30~\text{V}\), the required modification is to: 
1. connect resistor of \(\dfrac{x}{2}\Omega\), in series with voltmeter  
2. connect resistor of \(\dfrac{x}{2}\Omega\), in parallel to voltmeter
3. connect resistor of \(x~\Omega\) in series with voltmeter 
4. connect resistor of \(2x~\Omega\) in parallel to voltmeter 
Subtopic:  Conversion to Ammeter & Voltmeter |
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A moving coil galvanometer of resistance \(100~\Omega\) shows a full scale deflection for a current of \(1~\text{mA}.\) The value of resistance required to covert this galvanometer into an ammeter, showing full scale deflection for a current of \(5~\text{mA},\) is: (in \(\Omega\))​​
1. \(25\)
2. \(10\)
3. \(0.5 \)
4. \(2.5\)
Subtopic:  Conversion to Ammeter & Voltmeter |
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In the figure shown below, a resistance of \(150.4 ~\Omega\) is connected in series to an ammeter \(A\) of resistance \(240 ~\Omega\). A shunt resistance of \(10 ~\Omega\) is connected in parallel with the ammeter. The reading of the ammeter is: (in \(\text{mA}\))
                     
1. \(10\) 
2. \(5\) 
3. \(18\) 
4. \(25\)
Subtopic:  Conversion to Ammeter & Voltmeter |
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In the given figure, an ammeter \(A\) consists of a \(240~ \Omega\) galvanometer coil connected in parallel to a \(10~ \Omega\) shunt resistor. The reading of the ammeter is:
1. \(354~\text{mA}\) 2. \(160~\text{mA}\)
3. \(280~\text{mA}\) 4. \(79~\text{mA}\)
Subtopic:  Conversion to Ammeter & Voltmeter |
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A moving coil galvanometer has resistance \(50~\Omega\) and full deflection current is \(5~\text{mA}.\) The resistance needed to convert this galvanometer into a voltmeter of range \(100\) volt is:
1. \(19000~\Omega\)
2. \(18500~\Omega\)
3. \(19950~\Omega\)
4. \(18000~\Omega\)
Subtopic:  Conversion to Ammeter & Voltmeter |
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\(400~ \Omega\) series resistance is required to convert a galvanometer of \(100~ \Omega\) to a voltameter of range \(10~\text{V}.\) To convert the same galvanometer, in an ammeter of \(10~\text{A},\) the shunt resistance is:
1. \(4~ \Omega\)
2. \(0.4~ \Omega\)
3. \(0.2 ~\Omega\)
4. \(5~ \Omega\)
Subtopic:  Conversion to Ammeter & Voltmeter |
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Circuit I is converted to voltmeter after adding resistance R and current in circuit I is 1 mA. Circuit II is converted to ammeter after adding resistance r as shown. If current through battery in circuit II is 10 mA and current through galvanometer is 1 mA, then find R and r if resistance of galvanometer is 54 Ω.



1. R = 49946 Ω, r = 54 Ω
2. R = 6 Ω, r = 49946 Ω
3. R = 49946 Ω, r = 49946 Ω
4. R = 49946 Ω, r = 6 Ω

 
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\( 72 ~\Omega\) galvanometer is shunted by a resistance of \(8 ~\Omega.\) The percentage of the total current that passes through the galvanometer is:
1. \(0.1\%\)
2. \(10\%\)
3. \(25\%\)
4. \(0.25\%\)
Subtopic:  Conversion to Ammeter & Voltmeter |
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If \(n\) represents the actual number of deflections in a converted galvanometer of resistance \(G\) and shunt resistance \(S\). Then the total current \(I\) when its figure of merit is \(K\) will be:
1. \(\dfrac{KS}{(S+G)} \)
2. \(\dfrac{(G+S)}{nKS} \)
3. \(\dfrac{nKS}{(G+S)} \)
4. \(\dfrac{nK(G+S)}{S}\)
Subtopic:  Conversion to Ammeter & Voltmeter |
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