Voltage & Current Measurement -- Electrical Engineering (MCQ) questions and answers

1.Voltmeter is a galvanometer with ______

A. Both low and high resistance
B. Uncertain resistance
C. Low Resistance
D. High Reasistance

2. A moving-iron meter will operate on

A. AC circuit only
B. DC circuit only
C. Either AC and DC circuits
D. AC and DC when a rectifier is used

3. A generating voltmeter uses______

A. A variable speed motor
B. A variable speed motor with capacitor
C. A constant speed motor
D. None of these

4. Which of the following is not a feature of MI type instruments?

A. Can be used for both AC and DC
B. Uniformally divided scale
C. Moving element is a small soft iron piece
D. Low cost of instrument in comparison to moving coil instrument

5. Determine the value of current (in mA) for the full-scale deflection of a voltmeter. when the sensitivity of the voltmeter is 50ohm/volt.

A. 1
B. 2
C. 10
D. 20

6. Determine the value of shunt resistance (in ohms) required to convert a galvanometer into ammeter of reading upto 14A. When the internal resistance of the galvanometer is 27ohms and the value of current for full scale deflection is 0.5A.

A. 2.5Ω
B. 2Ω
C. 0Ω
D. 1Ω

7. How wil you convert galvanometer into ammeter?

A. Low resistance parallel to the galvanometer
B. High resistance parallel to galvanometer
C. Low resistance series to galvanometer
D.Low resistance series to galvanometer

8. Which one of the statement is not true about PMMC type instrument?

A. PMMC instruments have uniformally divided scale
B. Stray magnetic errors are small in these type of instrument
C. Cost of PMMC instruments are High
D. These instrument are suitable for both AC and DC currents

9. A PMMC type voltmeter, having a full scale reading of 250V and an internal resistance of 400KΩ, is connect with a series resistance of 100KΩ. Calculate the sensitivity of the voltmeter.

A.2000Ω/V
B. 2400Ω/V
C. 20000Ω/V
D. 24000Ω/V

10. What will happen to the operating torque of a moving iron instrument, if current through the operating coil is halved?

A. Double
B. Halved
C. One-fourth
D. Remain same

11. The range of moving coil instrument having meter resistance of 6ohm is 0-50V. Find the value of multiplying factor of the series resistance, if its full scale deflection current is 5A.

A. 1
B.1.5
C. 1.2
D. 1.67

12. A permanent magnet moving coil instrument has a coil of diamension 10mm*20mm. The flux density in the air gap is 2*10-3 Wb/m2 and the spring constant is 0.25*10-6 Nm/rad. If the current of 10mA is flowing through the coil, then calculate the number of turns required to produce an angular deflection of 60 degrees.

A. 40
B. 50
C. 60
D. 70

13. If zero centered voltmeter has a scale from -5V to +5V, then the span of it is

A. 5V
B. -5V
C. 10V
D. 0V

14. In a indicating instrument, the control torque produce by the spring is propotional to

A. θ2
B. θ
C. 1/θ
D. 1/θ2

15. ______ is used for temprature measurement

A. Rotameter
B. Venturimeter
C. Manometer
D.Thermocouple

16. Which one of the following types of watt-hour meter is used only in AC circuits?

A. Electrolytic type
B. Moving iron type
C. Moving coil type
D. Induction type meters

17. The analog meter will never have ____

A. ADC and DAC
B. A restraining spring
C. A scale
D. A pointer

18. Which of the following meters is most accurate instrument for measuring AC signals with frequencies lower than 200Hz?

A. Peak responding AC meter
B. Thermocuple meter
C. Clamp-on meter
D. Electrodynamometer movement

19. The accuracy of d'Arsonal movements used in common laboratory meters is about____ of the full-scale reading.

A. 1%
B. 10%
C. 9%
D. 0.1%

20. Megger is a instrument to measure

A. A very low resistance
B. Inductance of the coil
C. A very High resistance
D. Q of the coil