When a \(12~\Omega\) resistor is connected in parallel with a moving coil galvanometer, its deflection reduces from \(50\) divisions to \(10\) divisions. What will be the resistance of the galvanometer?
1. \(24~\Omega\)
2. \(36~\Omega\)
3. \(48~\Omega\)
4. \(60~\Omega\)
A voltmeter has a resistance of G ohms and range V volts. The value of resistance used in series to convert it into a voltmeter of range nV volts is :
1. nG
2.
3.
4.
Which of the following statement is wrong:
1. Voltmeter should have high resistance
2. Ammeter should have low resistance
3. Ammeter is placed in parallel across the conductor in a circuit
4. Voltmeter is placed in parallel across the conductor in a circuit
A moving coil galvanometer has a resistance of 50 Ωand gives full scale deflection for 10 mA. How could it be converted into an ammeter with a full scale deflection for 1A :
1. 50/99 Ω in series
2. 50/99 Ω in parallel
3. 0.01 Ω in series
4. 0.01 Ω in parallel
The resistance of an ideal voltmeter is
1. Zero
2. Very low
3. Very large
4. Infinite
The net resistance of a voltmeter should be large to ensure that :
1. | It does not get overheated |
2. | It draws excessive current |
3. | It can measure large potential difference |
4. | It does not appreciably change the potential difference to be measured |
A galvanometer having a resistance of \(8~\Omega\) is shunted by a wire of resistance \(2~\Omega\). If the total current is \(1~\text{A}\), the part of it passing through the shunt will be:
1. \(0.25~\text{A}\)
2. \(0.8~\text{A}\)
3. \(0.2~\text{A}\)
4. \(0.5~\text{A}\)
A voltmeter of resistance 1000 Ω gives full-scale deflection when a current of 100 mA flow through it. The shunt resistance required across it to enable it to be used as an ammeter reading 1 A at full-scale deflection is :
1. 10000 Ω
2. 9000 Ω
3. 222 Ω
4. 111 Ω
If an ammeter \(A\) reads \(2\) A and the voltmeter \(V\) reads \(20\) V, what is the value of resistance \(R\)? (Assuming finite resistances of ammeter and voltmeter)
1. | Exactly \(10~\Omega\) |
2. | Less than \(10~\Omega\) |
3. | More than \(10~\Omega\) |
4. | We cannot definitely say |
A galvanometer has a resistance of 25 ohm and a maximum of 0.01 A current can be passed through it. In order to change it into an ammeter of range 10 A, the shunt resistance required is
1. 5/999 ohm
2. 10/999 ohm
3. 20/999 ohm
4. 25/999 ohm