Electrical Indicating Instruments - Multiple Choice Questions and Answers

Electrical Indicating Instruments - Multiple Choice Questions and Answers Points : Electrical Indicating Instruments - Multiple Choice Questions and Answers, Objective type question electrical technology, Mcqs 1. Moving coil instruments are…..
(a) Permanent magnet type
(b) Dynamometer type
(c) Repulsion type
(d) Both (a) & (b)

2. Permanent magnet type instruments are suitable for…
(a) a.c. measurement
(b) d.c. measurement
(c) Neither (a) nor (b)
(d) Both (b) & (c)

3. PMMC instruments work on the principle of…….
(a) Faraday Law
(b) Lenz’s Law
(c) Current carrying conductor in a magnetic field
(d) Ampere turn

4. Controlling Torque in PMMC instrument is provided by.....
(a) Friction
(b) Air friction
(c) Hair springs
(d) All three

5. The scale in PMMC instrument is…..
(a) Linear
(b) Non-linear
(c) Cramped
(d) Both (b) & (c)

6. At final deflection position in PMMC instruments....
(a) rd
(b) r, r
(c) r, >rr
(d) v

7. Are the general types of moving iron instruments…
(a) Attraction type
(b) Repulsion type
(c) Static type
(d) Both (a)&(b)

8. Attraction type principle provides the basis for….
(a) D.C. meters
(b) A.C. meters
(c) A.C. & D.C. meters
(d) Digital meters

9. In attraction type instruments usually the damping is provided by….
(a) Air friction
(b) Eddy current
(c) Springs
(d) All of above

10. The exact calculation of deflecting torque in attraction type instrument is....
(a) Very simple
(b) Difficult
(c) Complex
(d) Easy

11. The temperature change error in dynamometers is minimized by.
(a) Hair springs
(b) Temperature compensating resistors
(c) Inductance
(d) Capacitor

12. In repulsion type moving iron instrument, the principle comes to rest when...
(a) Repulsion torque is greater than controlling force
(b) Less than controlling force
(c) Equilibrium is attained
(d) All of above

13. When repulsion type instrument is to be operated vertically, the controlling torque ie is produced by...
(a) Hair spring
(b) Gravity
(c) Both (a) & (b)
(d) Eddy current

14. The shape of scale of repulsion type instruments is….
(a) Uniform
(b) Unear
(c) Non-uniform
(d) All of above

15. The angular deflection in repulsion type instruments is proportional to....
(a) The square of current
(b) Type current
(c) The power input
(d) The power output

16. An electrodynamic type instrument is a…
(a) Moving iron type instrument
(b) Moving coil type instrument
(c) Electrostatic type instrument
(d) Hot wire type instrument

17. Electrodynamic principle can be used in....
(a) Ammeters
(b) Voltmeters
(c) Wattmeter & Frequency meter
(d) All of above

18. The fixed coil in dynamometer is divided in to two sections to give....
(a) Uniform field
(b) Non-uniform field
(c) Stray field
(d) All of above

19. The fixed coils in dynamometer are usually wound with heavy wire, because...
(a) To allow heavy currents
(b) To allow small currents
(c) To with stand high voltages

(d) All of above 20. The moving coil in dynamometer is wound on non-magnetic former to avoid...
(a) Heavy currents
(b) Eddy currents
(c) Hysteresis loss
(d) Both (b) & (C)

21. The moving system in dynamometer carries.
(a) Spindle
(b) Pointer
(c) Counter weights
(d) All of above

22. The purpose of shielding in dynamometer is....
(a) To produce eddy currents
(b) To protect against tray fields
(c) To avoid short circuiting
(d) Both (a) & (b)

23. When dynamometer used as a milliammeter, the fixed and moving coils may be connected in....
(a) Series
(b) Parallel
(c) Both (a) & (b)
(d) Open position

24. In dynamometers the coils are air cored to make the instrument free of....
(a) Eddy current error
(b) Hysteresis error
(c) Both (a) & (b)
(d) Phase angle error

25. The dynamometers have....
(a) Low torque/weight ratio
(b) High torque/weight ratio
(c) Zero torque/weight ratio
(d) Zero torque/weight ratio