A circuit contains an ammeter, a battery of \(30~\text{V}\), and a resistance \(40.8~\Omega\) all connected in series. If the ammeter has a coil of resistance \(480~\Omega\) and a shunt of \(20~\Omega\), then the reading in the ammeter will be:
1. \(0.5~\text{A}\)
2. \(0.02~\text{A}\)
3. \(2~\text{A}\)
4. \(1~\text{A}\)
In an ammeter, \(0.2 \%\) of the main current passes through the galvanometer. If the resistance of the galvanometer is \(G,\) the resistance of the ammeter will be:
1. | \({1 \over 499}G\) | 2. | \({499 \over 500}G\) |
3. | \({1 \over 500}G\) | 4. | \({500 \over 499}G\) |
A millivoltmeter of \(25~\text{mV}\) range is to be converted into an ammeter of \(25~\text{A}\) range. The value (in ohm) of the necessary shunt will be:
1. \(0.001\)
2. \(0.01\)
3. \(1\)
4. \(0.05\)
1. | \({G \over (S+G)}\) | 2. | \({S^2 \over (S+G)}\) |
3. | \({SG \over (S+G)}\) | 4. | \({G^2 \over (S+G)}\) |
1. | Putting in parallel, a resistance of \(24~ \Omega\) |
2. | Putting in series, a resistance of \(15~ \Omega\) |
3. | Putting in series, a resistance of \(240~ \Omega\) |
4. | Putting in parallel, a resistance of \(15~ \Omega\) |
What properties will a galvanometer that is acting as a voltmeter have?
1. | high resistance in series with its coil | 2. | low resistance in parallel with its coil |
3. | low resistance in series with its coil | 4. | high resistance in parallel with its coil |
A galvanometer of \(50~\Omega\) resistance has \(25\) divisions. A current of \(4\times 10^{-4}~\text{A}\) gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of \(25~\text{V}\), it should be connected with a resistance of:
1. | \(245~\Omega\) as a shunt |
2. | \(2550~\Omega\) in series |
3. | \(2450~\Omega\) in series |
4. | \(2500~\Omega\) as a shunt |
To convert a galvanometer into a voltmeter one should connect a:
1. | high resistance in series with the galvanometer. |
2. | low resistance in series with the galvanometer. |
3. | high resistance in parallel with the galvanometer. |
4. | low resistance in parallel with the galvanometer. |