Measurement MCQ Part-3

Measurement MCQs

1. A PMMC instrument can be used as a fluxmeter by________.

a. Using low resistance shunt

b. Removing the control springs

c. Making the control springs of large moment of inertia

d. Using a high series resistance

 

2. Flux meter is a special type of ballistic galvanometer provided with which one of the following ?

a. Large controlling torque and small electromagnetic damping

b. Small electromagnetic damping and controlling torque

c. Heavy electromagnetic damping and large controlling torque

d. Heavy electromagnetic damping and very small controlling torque

 

3. In a flux meter, the controlling torque is________.

a. Provided by crosses-coil mechanism

b. Produced by spring

c. Not provided at all

d. Produced by weight attached to the moving coil

 

4. What is connected across a flux meter for its effective functioning to measure magnetic flux density and also to compare the strengths of permanent magnets ?

a. A search coil

b. A capacitor

c. A transformer

d. A resistor

 

5. Analog panel meters basically measure_____.

a. Depends upon parameters

b. Power

c. Current

d. Voltage

 

6.  A moving coil galvanometer is made into a dc ammeter by connecting_________.

a. A capacitor in series with the meter

b. A pure inductance across the meter

c. A high resistance in series with the meter

d. A low resistance across the meter

 

7. The internal resistance of the milliammeter must be very low for ________.

a. Minimum effect on the current in the circuit

b. Maximum voltage drop across the meter

c. High accuracy

d. High sensitivity

 

8. A very accurate voltmeter gives inaccurate reading when used for measuring voltage across a low resistance because____________.

a. The higher scale has been selected

b. The voltmeter is making too low current

c. The meter sensitivity is too high

d. The meter sensitivity is too low

 

9. Which one of the following statement is correct ?

Spiral springs are used in instruments to

a. Provide controlling torque

b. Provide damping torque

c. Lead the current to the moving coil as well as to provide the controlling torque

d. Provide linear deflection

 

10. A mangnin swamp resistance is connected in series with a moving coil ammeter consisting of a milliammeter and suitable shunt in order to________.

a. Minimize the effect of stray magnetic fields

b. Reduce the size of the meter

c. Obtain large deflecting torque

d. Minimize the effect of temperature variation

 

11. Eddy current damping cannot be used for moving iron instruments because_______.

a. Weight of the instrument will increase

b. Size of the instrument will increase

c. Presence of permanent magnet will distort the magnetic field produced by the instrument and hence will affect its readings

d. Eddy currents will pass through the iron thereby cause losses

 

12. Hysteresis error, in moving iron instruments, may be reduced by using_______.

a. High speed steel

b. Silver coating

c. Stainless steel

d. Permalloy

13. An advantage of a PMMC instrument is that it is________.

a. Free from Friction error

b. Has high(torque/weight of the moving parts) ratio

c. Has low(torque/weight of the moving parts) ratio

d. can be used on both ac and dc

 

14. The term artificial aging is associated with__________.

a. Damping

b. Controlling torques

c. Permanent magnets

d. Springs

 

15. Moving iron and PMMC instrument can be distinguished from each other by looking at______.

a. Scale range

b. Terminal size

c. Pointer

d. Scale

 

16. The scale of a dynamometer type instrument marked in terms of rm value would be______.

a. Nonuniform crowded around midscale

b. Nonuniform crowded at the beginning

c. Nonuniform crowded  near full scale

d. Uniform throughout

 

17. In a dynamometer type moving coil instrument a swamping resistance is provided in order to______.

a. Provide equal time constant for moving coil and fixed coil, when used for ac measurement

b. Reduce the current flowing through the moving coil

c. Reduce the bulk of the moving system

d. Control the deflecting torque

 

18. Electrodynamometer type of instrument can be used to measure ______.

a. AC only

b. DC only

c. Both AC and DC

d. None of the above

 

19. Which one of the following statement is correct?

The deflection of a hot-wire instrument depends on_______.

a. Average value of the ac voltage

b. Average value of the ac current

c. RMS value of the ac voltage

d. RMS value of the ac current

 

20. Which of the following statements is not correct for thermocouple measuring instruments?

a. Their calibration does not change with time or temperature

b. Power losses are very low

c. They are incapable of taking any overload

d. They are very useful as transfer instruments

 

21. Rectifier moving coil instrument respond to______.

a. RMS value, for symmetrical square waveforms

b. RMS value for all waveforms

c. Average value, for all waveforms

d. Peak value, irrespective of the nature of the waveform

 

22. Which of the following meters does not exhibit square law response?

a. Hot wire instrument

b. Electrodynamometer

c. Moving iron

d. Moving coil

 

23. Which one of the following instruments is commonly used to measure the primary current of a transformer connected to mains?

a. Moving iron meter

b. Moving coil type meter

c. Current transformer

d. Electrostatic meter

 

24. Decibel scale is useful while measuring voltages covering_______.

a. Narrow voltage range

b. Narrow frequency range

c. Wide voltage ratio

d. Wide frequency ratio

 

25. To measure current in the MHz range, we use an instrument of________.

a. Rectifier type

b. Electrodynamometer type

c. Thermocouple type

d. Moving iron type