electronic instruments MCQs

Practise focused electronic instruments questions with marked answers for exam preparation and subject revision.

electronic instruments Mcqs
1. Two multimeters A and B have sensitivities of 10 kO/V and 30 kO/V respectively. Then ______________?
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A. Multimeter A is more sensitive

B. Multimeter B is more sensitive

C. Both are equally sensitive

D. None of the above

2. A VTVM is never used to measure ______________?
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A. None of the above

B. Resistance

C. Voltage

D. Current
3. Which of the following is likely to have the largest resistance ?
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A. Moving coil galvanometer

B. A copper wire of length 1 m and diameter 3 mm

C. Ammeter of range 1 A

D. Voltmeter of range 10 V
4. A series ohmmeter circuit uses a 3 V battery and a 1 mA meter movement. What is the half-scale resistance for this movement ?
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A. 3 kO

B. kO

C. 6 kO

D. kO

5. 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________________?
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A. (n-1)G

B. G/(n-1)

C. nG

D. G/n

6. The most accurate device for measuring voltage is ____________?
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A. Voltmeter

B. VTVM

C. CRO

D. Multimeter

7. The resistance of an ideal voltmeter is ______________?
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A. Low

B. Infinite

C. High

D. Zero

8. The materil used to coat inside the face of CRT is ______________?
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A. Silicon

B. Carbon

C. Sulphur

D. Phosphorous
9. If the negative potential on the control grid of CRT is increased, the intensity of spot _____________?
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A. Remains the same

B. Is decreased

C. None of the above

D. Is increased

10. A galvanometer in series with a high resistance is called_______________?
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A. A voltmeter

B. An ammeter

C. None of the above

D. A wattmeter

11. A galvanometer of resistance G is shunted by a very small resistance S. The resistance of the resulting ammeter is ______________?
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A. G-S

B. None of the above

C. G+S

D. GS/(G+S)
12. An ideal ammeter has ______________ resistance?
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A. Infinite

B. High

C. Zero

D. Low

13. The sensitivity of a multimeter is given in _______________?
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A. O

B. kO/V

C. none of the above

D. Amperes

14. A voltmeter should have ____________resistance?
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A. Very high

B. Very low

C. Zero

D. None of the above

15. The horizontal plates of a CRO are supplied with _____________ to observe the waveform of signal?
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A. Cosine wave

B. Sawtooth wave

C. Sinusoidal wave

D. None of the above

16. For display of signal pattern _____________voltage is applied to the horizontal plates of a CRO?
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A. Sawtooth

B. Rectangular

C. None of the above

D. Sinusoidal

17. If the full-scale deflection current of a multimeter is 50 A, its sensitivity is ________________?
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A. 50 kO/V

B. 20 kO/V

C. 10 kO/V

D. 100 kO/V

18. 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______________?
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A. G/(n-1)

B. G/n

C. (n-1)G

D. nG

19. An ammeter is connected in __________ with the circuit element whose current we wish to measure?
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A. None of the above

B. Series

C. Series or parallel

D. Parallel

20. A VTVM has_____________input resistance than that of a multi meter?
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A. Same

B. None of the above

C. Less

D. More
21. A CRO is used to measure _________________?
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A. Phase

B. Voltage

C. Frequency

D. All of above
22. When an ammeter is inserted in the circuit, the circuit current will _____________?
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A. Increase

B. None of the above

C. Remain the same

D. Decrease
23. To send 10% of the main current through a moving coil galvanometer of resistance 99 O the shunt required is______________?
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A. 100 O

B. 9 O

C. 11 O

D. 9 O

24. The input resistance of a VTVM is about ______________?
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A. 10 MO

B. 10 kO

C. 1000 O

D. 20 kO

25. If 2% of the main current is to be passed through a galvanometer of resistance G, then resistance of the shunt required is ________________?
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A. G/50

B. G/49

C. 49 G

D. 50 G

26. An ammeter should have_____________ resistance?
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A. Very low

B. None of the above

C. Infinite

D. Very large

27. What is the total resistance of a voltmeter on the 10 V range when the meter movement is rated for 50 A of full-scale current ?
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A. 20 kO

B. 200 kO

C. None of the above

D. 10 kO

28. A voltmeter is connected in a _____________ with the circuit component across which potential difference is to be measured?
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A. Series or parallel

B. Parallel

C. None of the above

D. Series

29. If a multimeter has a sensitivity of 1000 O per volt and reads 50 V full scale, its internal resistance is _____________?
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A. 20 kO

B. None of the above

C. 10 kO

D. 50 kO
30. The sensitivity of a voltmeter which uses a 100 A meter movement is ____________?
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A. 10 kO/V

B. 5 kO/V

C. 1 kO/V

D. Data insufficient