Wattmeter MCQ

61. Moving iron type meter has nonlinear scale as

  1. θ ∝ I2rms
  2. θ ∝ R2
  3. θ ∝ Vrms
  4. θ ∝ Irms
Answer
Answer. a

62. In measuring instruments, the damping force can be produced by

  1. Commutator
  2. Moving coil
  3. Eddy current
  4. Supply current
Answer
Answer. c

63. The active and apparent power an inductive circuit is 60KW and 100KVA respectively. The power factor of the circuit is

  1. 0.6 leading
  2. 0.6 lagging
  3. 0.5 lagging
  4. 0.75 lagging
Answer
Answer. b

64. Two wattmeter method can be used to measure the total power delivered to

  1. Star connected with neutral loads
  2. Delta connected load only
  3. Star connected load only
  4. Star as well as delta connected loads
Answer
Answer. d

65. The type of wattmeter commonly used for measurement of power in AC circuits is

  1. Moving iron type
  2. Thermocouple type
  3. Rectifier type
  4. Dynamometer type
Answer
Answer. d

66. A demand meter is a means of indicating which of the following?

  1. Peak power periods
  2. A high load factor
  3. Low kWh consumption
  4. All options are correct
Answer
Answer. d

67. What does the reading of the first dial on the right of a 4-dial watt-hour meter indicate?

  1. Number of single units
  2. Total watts each hour
  3. Maximum value the meter can register
  4. Multiplier value of the preceding dial
Answer
Answer. a

68. In dynamometer type of wattmeter, which of the coil is split up into two parts?

  1. pressure coil
  2. current coil
  3. both the pressure coil and current coil
  4. None of these
Answer
Answer. b

69. Which of the following does a power factor meter indicate?

  1. Continuous power
  2. Power difference between phases
  3. The current is leading or lagging the voltage
  4. Reactive and useful power
Answer
Answer. c

70. If a wattmeter is used in a circuit it is safe voltage or current rating is exceeded, the meter will

  1. not be affected
  2. operated erratically
  3. immediately peg the pointer
  4. not indicate the overload
Answer
Answer. d