# EE AND ECE IMPORTANT MCQ PDF- Electronic Instruments 1

Q1. 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

Q2. A galvanometer in series with a high resistance is called ……………

1. An ammeter
2. A voltmeter
3. A wattmeter
4. None of the above

Q3. An ammeter should have ………….. resistance

1. Infinite
2. Very large
3. Very low
4. None of the above

Q4. A voltmeter is connected in a ………….. 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

Q5. A voltmeter should have ………. resistance

1. Zero
2. Very high
3. Very low
4. None of the above

Q6. The sensitivity of a multimeter is given in ……………..

1. Ω
2. Amperes
3. kΩ/V
4. none of the above

Q7. If the full-scale deflection current of a multimeter is 50 μA, its sensitivity is ……..

1. 10 kΩ/V
2. 100 kΩ/V
3. 50 kΩ/V
4. 20 kΩ/V

Q8. If a multimeter has a sensitivity of 1000 Ω per volt and reads 50 V full scale, its internal resistance is ………..

1. 20 kΩ
2. 50 kΩ
3. 10 kΩ
4. None of the above

Q9.  A VTVM has ………. input resistance than that of a multimeter

1. More
2. Less
3. Same
4. None of the above

Q10. The input resistance of a VTVM is about ………..

1. 1000 Ω
2. 10 kΩ
3. 20 kΩ
4. 10 MΩ

Q11. If the negative potential on the control grid of CRT is increased, the intensity of spot ………….

1. Is increased
2. Is decreased
3. Remains the same
4. None of the above

Q12. For display of signal pattern ………… voltage is applied to the horizontal plates of a CRO

1. Sinusoidal
2. Rectangular
3. Sawtooth
4. None of the above

Q13. Two multimeters A and B have sensitivities of 10 kΩ/V and 30 kΩ/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

Q14. 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

Q15. A VTVM is never used to measure …………..

1. Voltage
2. Current
3. Resistance
4. None of the above

Q16. The sensitivity of a voltmeter which uses a 100 μA meter movement is ……………..

1. 1 kΩ/V
2. 10 kΩ/V
3. 5 kΩ/V
4. Data insufficient

Q17. 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 kΩ
2. 20 kΩ
3. 200 kΩ
4. None of the above

Q18. The materil used to coat inside the face of CRT is …………..

1. Carbon
2. Sulphur
3. Silicon
4. Phosphorous

Q19. 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

Q20. 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 kΩ
2. 6 kΩ
3.  4 kΩ
4.  2 kΩ

Q21. The most accurate device for measuring voltage is ………….

1. Voltmeter
2. Multimeter
3. CRO
4. VTVM

Q22. The horizontal plates of a CRO are supplied with …………. to observe  the waveform of signal.

1. Sinusoidal wave
2. Cosine wave
3. Sawtooth wave
4. None of the above

Q23. A CRO is used to measure ………….

1. Voltage
2. Frequency
3. Phase
4. All of above

Q24. If 2% of the main current is to be passed through a
galvanometer of resistance G, then resistance of the shunt required is
……….

1. G/50
2. G/49
3. 49 G
4. 50 G

Q25. 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

Q26. An ideal ammeter has ………… resistance

1. Low
2. Infinite
3. Zero
4. High

Q27. The resistance of an ideal voltmeter is …………

1. Low
2. Infinite
3. Zero
4. High

Q28. To send 10% of the main current through a moving coil galvanometer of resistance 99 Ω the shunt required is …………..

1. 11 Ω
2. 9 Ω
3. 100 Ω
4. 9 Ω

Q29. 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