# Objective Questions on Electronic Instruments

## Objective Questions on Electronic Instruments

Objective Questions on Electronic Instruments, Electronic Instruments MCQ, Multiple Choice Questions on Electronic Instruments, Objective Questions on Electronic Instruments, GATE Questions on Electronic Instruments MCQ, Engineering MCQ, Instrumentation MCQ, EMI MCQ.

### Multiple Choice Questions

Q.1. An ammeter is connected in …………… with the circuit element whose current we wish to measure.

• series
• parallel
• series or parallel
• none of the above

Q.2. A galvanometer in series with a high resistance is called …………………………

• an ammeter
• a voltmeter
• a wattmeter
• none of the above

Q.3. An ammeter should have …………… resistance.

• infinite
• very large
• very low
• none of the above

Q.4. A voltmeter is connected in …………… with the circuit component across which potential difference is to be measured.

• parallel
• series
• series or parallel
• none of the above

Q.5. A voltmeter should have ………….. resistance.

• zero
• very high
• very low
• none of the above

Q.6. The sensitivity of a multimeter is given in ……………

• Ω
• amperes
• kΩ/V
• none of the above

Q.7. If the full-scale deflection current of a multimeter is 50 μA, its sensitivity is ……………

• 10 kΩ/V
• 100 kΩ/V
• 50 kΩ/V
• 20 kΩ/V

Q.8. If a multimeter has a sensitivity of 1000 Ω per volt and reads 50 V full scale, its internal resistance is……………

• 20 kΩ
• 50 kΩ
• 10 kΩ
• none of the above

Q.9. A VTVM has …………… input resistance than that of a multimeter.

• more
• less
• same
• none of the above

Q.10. The input resistance of a VTVM is about ……………

• 1000 Ω
• 10 kΩ
• 20 kΩ
• 10 MΩ

Q.11. If the negative potential on the control grid of CRT is increased, the intensity of spot ……………

• is increased
• is decreased
• remains the same
• none of the above

Q.12. For display of signal pattern …………… voltage is applied to the horizontal plates of a CRO.

• sinusoidal
• rectangular
• sawtooth
• none of the above

Q.13. Two multimeters A and B have sensitivities of 10 kΩ/V and 30 kΩ/V respectively. Then ……………

• multimeter A is more sensitive
• multimeter B is more sensitive
• both are equally sensitive
• none of the above

Answer: multimeter B is more sensitive

Q.14. A galvanometer of resistance G is shunted by a very small resistance S. The resistance of the resulting ammeter is ……………

• $\frac{GS}{G+S}$
• $G+S$
• $G-S$
• None of the above

Answer: $\frac{GS}{G+S}$

Q.15. A VTVM is never used to measure ……………

• voltage
• current
• resistance
• none of the above

Q.16. The sensitivity of a voltmeter that uses a 100 μA meter movement is ……………

• 1 kΩ/V
• 10 kΩ/V
• 5 kΩ/V
• data insufficient

Q.17. 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?

• 10 kΩ
• 20 kΩ
• 200 kΩ
• none of the above

Q.18. The material used to coat the inside face of CRT is ……………

• carbon
• sulphur
• silicon
• phosphorus

Q.19. When an ammeter is inserted in the circuit, the circuit current will ……………

• increase
• decrease
• remain the same
• none of the above

Q.20. A series ohmmeter circuit uses a 3 V battery and a 1 mA meter movement. What is the half-scale resistance for this movement?

• 3 kΩ
• 1.5 kΩ
• 4.5 kΩ
• 6 kΩ

Q.21. The most accurate device for measuring voltage is ……………

• voltmeter
• multimeter
• CRO
• VTVM

Q.22. The horizontal plates of a CRO are supplied with …………… to observe the waveform of a signal.

• sinusoidal wave
• cosine wave
• sawtooth wave
• none of the above

Q.23. A CRO is used to measure ……………

• voltage
• frequency
• phase
• all of above

Q.24. If 2 % of the main current is to be passed through a galvanometer of resistance G, then resistance of the shunt required is ………….

• G/50
• G/49
• 49 G
• 50 G

Q.25. Which of the following is likely to have the largest resistance ?

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

Answer: voltmeter of range 10 V

Q.26. An ideal ammeter has …………… resistance.

• low
• infinite
• zero
• high

Q.27. The resistance of an ideal voltmeter is ………

• low
• infinite
• zero
• high

Q.28. To send 10% of the main current through a moving coil galvanometer of resistance 99 Ω, the shunt required is ……………

• 11 Ω
• 9.9 Ω
• 100 Ω
• 9 Ω

Q.29. 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 …………………

• $nG$
• $\frac{G}{n}$
• $\frac{G}{n-1}$
• $(n-1)G$

Answer: $(n-1)G$

Q.30. 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 ………………..

• $nG$
• $(n-1)G$
• $\frac{G}{n-1}$
• $\frac{G}{n}$

Answer: $\frac{G}{n}$

Cathode Ray Oscilloscope (CRO) MCQ

MCQ on Measurement and Instrumentation