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Chapter 3 Ammeters and Voltmeters MCQs

1. Internal resistance of an ampere meter is

(A) Both b & c


(B) Very high


(C) Medium


(D) Very low




2. Ampere meter is connected

(A) Both in series & parallel


(B) In parallel of the circuit


(C) In series of the load


(D) None of these




3. If an ampere meter is connected in parallel of the circuit.

(A) It will give no reading


(B) Will not burn


(C) It will burn out promptly


(D) It will give proper reading




4. Internal resistance of a volt meter is

(A) Very low


(B) Very high


(C) Medium


(D) Low




5. If a voltmeter is connected in parallel of the circuit (its range is suitable for supply voltage).

(A) It will give correct reading


(B) It will not give correct reading


(C) It will burn promptly


(D) Both a & b




6. If a voltmeter is connected in series of the load

(A) It will not burn but it will not give correct reading


(B) It will not burn & will give correct reading


(C) It will burn promptly


(D) None of these




7. Ampere turns of the coils of a moving iron voltmeter and moving coil ampere meter

(A) Not a nor b


(B) There is no difference


(C) There is lot of difference


(D) There is no ampere turns in it




8. Coil of moving iron voltmeter is made with

(A) Many turns of thin wire


(B) Few turns of thin wire


(C) Many turns of thick wire


(D) Few turns of thick wire




9. In permanent magnet moving coil instruments

(A) Two control springs are used


(B) One control spring is used


(C) One moving coil is used


(D) Both a & c




10. Coil former of PMMC instruments is made in

(A) Rectangular form made of copper


(B) Rectangular form made of aluminium


(C) Circular form made of copper


(D) Both a & b




11. Permanent magnet moving coil instruments are used on

(A) A.C Supply


(B) D.C supply


(C) Both A.C & D.C Supply


(D) All types of supply




12. Diameter of wire of coil in a Permanent magnet moving coil instruments use is

(A) None of these


(B) 0.02 to 0.2 cm


(C) 10 to 15 mm


(D) 0.02 to 0.2 mm




13. Purpose of cylindrical core in the Permanent magnet moving coil instruments is

(A) To prevent the instrument from getting heated up


(B) To provide eddy current damping


(C) To prevent the magnetic lines of force not to strike on coil


(D) To concentrate the magnetic lines of force on coil




14. This is used in Permanent magnet moving coil instruments.

(A) One static coil and one permanent magnet


(B) One moving coil and one permanent magnet


(C) One static coil and two permanent magnets


(D) One moving coil and one electro magnet




15. This is used in Permanent magnet moving coil instruments.

(A) Electro magnet


(B) Bar magnet


(C) Horse shoe magnet


(D) None of these




16. The scale of Permanent magnet moving coil instruments is

(A) Square law scale


(B) Non linear


(C) Linear


(D) Both a & c




17. The damping method used in permanent magnet moving coil instruments is

(A) Fluid friction method


(B) Eddy current method


(C) Air friction method


(D) Both a & c




18. Permanent magnet moving coil instruments have

(A) None of these


(B) Low torque to weight ratio


(C) Medium torque to weight ratio


(D) High torque to weight ratio




19. Permanent magnet moving coil instruments use power

(A) 25 to 200 μW


(B) 50 to 100 mW


(C) 25 to 50 mW


(D) 0.1 to 0.5 μW




20. The over load capacity of permanent magnet moving coil instruments is

(A) Very high


(B) High


(C) Low


(D) Medium




21. The length of scale of permanent magnet moving coil instruments is

(A) Up to 300°


(B) Up to 360°


(C) Up to 100°


(D) Up to 50°




22. This error does not occur in permanent magnet moving coil instruments.

(A) Frictional error


(B) Error due to change in frequency


(C) Error due to stray magnetic field


(D) Error due to thermoelectric e.m.f




23. Dynamometer type instruments are basically

(A) Moving iron type


(B) Thermal type


(C) Moving coil type


(D) Induction type




24. Dynamometer type instruments are used on

(A) AC supply


(B) DC supply


(C) Both AC & DC supply


(D) Rectified AC supply




25. Scale of dynamometer type instruments have

(A) Separate scale for AC and DC supply


(B) Scale for AC supply


(C) Supply


(D) Same scale for AC and DC supply




26. Cores of fixed and moving coils of dynamometer type instruments are made air core to

(A) To avoid iron loss


(B) To reduce the weight of the instrument


(C) Both a & b


(D) None of the above




27. The number of moving coils used in dynamometer type instruments

(A) Four


(B) Two


(C) Three


(D) One




28. Are called “transfer” instruments because

(A) They transfer power to the circuit


(B) They can easily be transferred to other type of instruments


(C) Use only one scale for AC and DC supply


(D) They transfer measured quantity to other instruments




29. These instruments give true reading even on the non sinusoidal wave form of AC supply

(A) Both a & b


(B) Rectifier type instruments


(C) Dynamometer type instruments


(D) None of these




30. Dynamometer type instruments usually have

(A) Two fix and two moving coils


(B) One fix and two moving coils


(C) One fix and one moving coil


(D) Two fix and one moving coil




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