Electronic Instruments Multiple Choice Questions and Answers

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