Electronic Instruments MCQs Quiz Multiple Choice Questions & Answers

1. A galvanometer in series with a high resistance is called ..................

1. an ammeter
2. a voltmeter
3. a wattmeter
4. none of the above

2. A galvanometer of resistance G is shunted by a very small resistance S. The resistance of the resulting ammeter is ...............

1. GS/(G + S)
2. G + S
3. G - S
4. none of the above

3. A series ohmmeter circuit uses a 3 V battery and a 1 mA meter movement. What is the half-scale resistance for this movement ?

1. 3 kohm
2. 1.5 kohm
3. 4.5 kohm
4. 6 kohm

4. A voltmeter has a resistance of G ohms and range V volts. The value of resistance required in series to convert it into voltmeter of range nV is .....................

1. nG
2. G/n
3. G/(n - 1)
4. (n - 1)G

5. A voltmeter is connected in ............... with the circuit component across which potential difference is to be measured

1. parallel
2. series
3. series or parallel
4. none of the above

6. A voltmeter should have .............. resistance

1. zero
2. very high
3. very low
4. none of the above

7. A VTVM has ............... input resistance than that of a multimeter

1. more
2. less
3. same
4. none of the above

8. A VTVM is never used to measure ...............

1. voltage
2. current
3. resistance
4. none of the above

9. An ammeter has a resistance of G ohms and range of I amperes. The value of resistance required in parallel to convert it into an ammeter of range nI is ....................

1. nG
2. (n - 1)G
3. G/(n - 1)
4. G/n

10. An ammeter is connected in ............... with the circuit element whose current we wish to measure

1. series
2. parallel
3. series or parallel
4. none of the above

11. An ammeter should have ............... resistance

1. infinite
2. very large
3. very low
4. none of the above

12. An ideal ammeter has ............... resistance

1. low
2. infinite
3. zero
4. high

13. The input resistance of a VTVM is about ............

1. 1000 ohm
2. 10 kohm
3. 20 kohm
4. 10 Mohm

14. The resistance of an ideal voltmeter is .........

1. low
2. infinite
3. zero
4. high

15. The sensitivity of a multimeter is given in ...........

1. ohm
2. amperes
3. kohm/V
4. none of the above

16. The sensitivity of a voltmeter which uses a 100 micro Amperes meter movement is ...............

1. 1 kohm/V
2. 10 kohm/V
3. 5 kohm/V
4. data insufficient

17. To send 10 percent of the main current through a moving coil galvanometer of resistance 99 ohms, the shunt required is ...............

1. 11 ohm
2. 9.9 ohm
3. 100 ohm
4. 9 ohm

18. Two multimeters A and B have sensitivities of 10 kohms/V and 30 kohms/V respectively. Then ...............

1. multimeter A is more sensitive
2. multimeter B is more sensitive
3. both are equally sensitive
4. none of the above

19. What is the total resistance of a voltmeter on the 10 V range when the meter movement is rated for 50 µA of full-scale current ?

1. 10 kohms
2. 20 kohms
3. 200 kohms
4. none of the above

20. When an ammeter is inserted in the circuit, the circuit current will ...............

1. increase
2. decrease
3. remain the same
4. none of the above

21. Which of the following is likely to have the largest resistance ?

1. voltmeter of range 10 V
2. moving coil galvanometer
3. ammeter of range 1 A
4. a copper wire of length 1 m and diameter 3 mm