Ammeter MCQ

21. An ammeter has a current range of 0—5 A, and its internal resistance is 0.2 ohm in order to change the range to 0—25 A, we need to add a resistance of

  1. 0.05 ohm in parallel with the meter
  2. 0.04 ohm in parallel with the meter
  3. 1.0 ohm in series with the meter
  4. 0.8 ohm in series with the meter
Answer
Answer. a

22. An ammeter of 0—25 A range has guarantee accuracy of 1% of full scale reading. The current measured is 5 A. The limiting error is

  1. 0.05
  2. 0.04
  3. 0.025
  4. 0.02
Answer
Answer. a

23. A galvanometer may be converted into ammeter or voltmeter. In which of the following cases the resistance of the device will be the largest?

  1. An ammeter of range 10 A
  2. A voltmeter of range 5 V
  3. An ammeter of range 5 A
  4. A voltmeter of range 10 V
Answer
Answer. d

24. For a given frequency, the deflection torque of an induction ammeter is directly proportional to:

  1. (current)2
  2. (current)3
  3. (current)½
  4. (current)
Answer
Answer. a

25. Which of the following is correct about a clamper?

  1. It preserves the signal shape But changes the DC level.
  2. It changes signal shape But preserves the DC level
  3. It preserves signal shape as well as DC level
  4. It changes both signal shape and DC level
Answer
Answer. a

26. The deflecting torque of an ammeter is directly proportional to the current passing through it and the instrument has a full-scale deflection of 90° for a current of 10 A. What deflection will occur for a current of 5 A when the instrument has gravity control?

  1. 30°
  2. 45°
  3. 60°
  4. 90°
Answer
Answer. a

27. A meter  movement with current sensitivity 100 μA and internal resistance 100 Ω is required to measure the current of 10 mA. What will the shunt resistance be equal to?

  1. 1 Ω
  2. 0.98 Ω
  3. 0.99 Ω
  4. 1.010101 Ω
Answer
Answer. d

28. A 1 mA D’Arsonval movement has a resistance of 100 ohms. It is to be converted to a 10 V voltmeter. The value of multiplier resistance is

  1. 999 Ω
  2. 9999 Ω
  3. 9900 Ω
  4. 990 Ω
Answer
Answer. c

29. If an ammeter & a capacitor are connected in series on D.C. circuit the ammeter will

  1. Give continuous reading
  2. Initially give& then will come to zero
  3. Not give any reading
  4. Give only half the reading
Answer
Answer. b

30. The range of a permanent magnet moving coil instrument used as an Ammeter can be increased by

  1. Connecting a high resistance in series with the instrument
  2. Connecting a low resistance in series with the instrument
  3. Connecting a low resistance in parallel with the instrument
  4. Connecting a high resistance in parallel with the instrument
Answer
Answer. c
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