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
A galvanometer has 30 divisions and a sensitivity 16 It can be converted into a voltmeter to read 3 V by connecting (approximately):
(1) Resistance nearly 6 k Ω in series
(2) 6 k Ω in parallel
(3) 500 Ω in series
(4) It cannot be converted
A voltmeter has a range 0-V with a series resistance R. With a series resistance 2R, the range is 0-V'. The correct relation between V and V' is :
(1)
(2)
(3)
(4)
If an ammeter is to be used in place of a voltmeter then we must connect with the ammeter a :
(1) Low resistance in parallel
(2) High resistance in parallel
(3) High resistance in series
(4) Low resistance in series
1. | \(\dfrac{1}{40}\) | 2. | \(\dfrac{1}{4}\) |
3. | \(\dfrac{1}{140}\) | 4. | \(\dfrac{1}{10}\) |