Ammeter MCQ

31. The value of resistances in a potential divider arrangement to convert a basic d’arsonval meter movement with an internal resistance of 100 ohms and  a full-scale current of 1 mA to a multi-range DC voltmeter with ranges 0—150 V and 0—300 V are

  1. 149.5 kΩ, 155.5 kΩ
  2. 144.9 kΩ,140 kΩ
  3. 135.5 kΩ, 134 kΩ
  4. 149.9 kΩ,150 kΩ
Answer
Answer. d

32. A PMMC meter has an internal resistance of 200 Ω and the current required for its full scale deflection is 50μA. The meter is capable of measuring on its own a maximum voltage of

  1. 50 μV
  2. 10 μV
  3. 5 mV
  4. 10 mV
Answer
Answer. d

33. Which of the following is not a requirement for a DC ammeter’s shunt?

  1. High thermal automotive force
  2. Time-invariant
  3. Low temperature coefficient
  4. Carry current without excessive temperature rise
Answer
Answer. a

36. A moving-coil permanent-magnet instrument can be used as ______ by using a low resistance shunt

  1. Voltmeters
  2. Ammeters
  3. Ohmmeters and resistance bridges
  4. All of these
Answer
Answer. b

37. The instrument transformers are normally used to extend the range of

  1. Induction instruments
  2. Electrostatic instruments
  3. Moving iron instruments
  4. All of these
Answer
Answer. c
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