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 ohms is shunted by a wire of resistance 2 ohms. If the total current is 1 amp, the part of it passing through the shunt will be :
(1) 0.25 amp
(2) 0.8 amp
(3) 0.2 amp
(4) 0.5 amp
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 ohm |
2. | Less than 10 ohm |
3. | More than 10 ohm |
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