Sail E0 Webinar

MCQs

Total Questions : 103 | Page 2 of 11 pages
Question 11. A circuit is used to measure the power consumed by the load. The current coil and the voltage coil of the watt-meter have 0.02 Ω and 1000 Ω resistances respectively. The measured power (as compared to the load power) will be?
  1.    0.4 % less
  2.    0.2 % less
  3.    0.2 % more
  4.    0.4 % more
 Discuss Question
Answer: Option C. -> 0.2 % more
Answer: (c).0.2 % more
Question 12. The line to line input voltage to the 3-phase, 50 Hz, AC circuit, is 100 V rms. Assuming that the phase sequence is RYB; the watt-meters would read?
  1.    W₁ = 886 W and W₂ = 886 W
  2.    W₁ = 500 W and W₂ = 500 W
  3.    W₁ = 0 W and W₂ = 1000 W
  4.    W₁ = 250 W and W₂ = 750 W
 Discuss Question
Answer: Option C. -> W₁ = 0 W and W₂ = 1000 W
Answer: (c).W₁ = 0 W and W₂ = 1000 W
Question 13. A sampling watt-meter is used to measure the average power of a load. The peak to peak voltage of the square wave is 10 V and the current is a triangular wave of 5A p-p. The reading in watt will be?
  1.    Zero
  2.    25 W
  3.    50 W
  4.    100 W
 Discuss Question
Answer: Option A. -> Zero
Answer: (a).Zero
Question 14. A 3-phase, 600 V motor, the load having 0.6 power factor uses two watt-meter to measure the power. If the power measured be 45 kW, then the reading of each instrument will be?
  1.    P₁ = 35 kW, P₂ = 10 kW
  2.    P₁ = 47.25 kW, P₂ = -2.25 kW
  3.    P₁ = 39.82 kW, P₂ = 5.179 kW
  4.    P₁ = 45 kW, P₂ = 0 kW
 Discuss Question
Answer: Option C. -> P₁ = 39.82 kW, P₂ = 5.179 kW
Answer: (c).P₁ = 39.82 kW, P₂ = 5.179 kW
Question 15. The meter constant of a single-phase, 100 V induction watt-meter is 600 rev/kW-h. The speed of the meter disc for a current of 15 A at 0.8 power factor lagging will be?
  1.    30.3 rpm
  2.    16 rpm
  3.    12 rpm
  4.    33.1 rpm
 Discuss Question
Answer: Option C. -> 12 rpm
Answer: (c).12 rpm
Question 16. Pressure coil of a wattmeter ________
  1.    has capacitance and inductance
  2.    has inductance and resistance
  3.    has resistance and capacitance
  4.    has only inductance
 Discuss Question
Answer: Option A. -> has capacitance and inductance
Answer: (a).has capacitance and inductance
Question 17. Wattmeter reading has errors induced by _________
  1.    resistance
  2.    self-capacitance
  3.    self-inductance
  4.    mutual inductance
 Discuss Question
Answer: Option D. -> mutual inductance
Answer: (d).mutual inductance
Question 18. Wattmeter reading is not affected by temperature.
  1.    True
  2.    False
  3.    May be True or False
  4.    Can't say
 Discuss Question
Answer: Option B. -> False
Answer: (b).False
Question 19. What is the effect of capacitance on wattmeter reading?
  1.    aiding the inductance
  2.    opposite to that of inductance
  3.    aiding the capacitance
  4.    opposite to that of resistance
 Discuss Question
Answer: Option B. -> opposite to that of inductance
Answer: (b).opposite to that of inductance
Question 20. Dynamometer type wattmeter has _________
  1.    strong magnetic field
  2.    intermediate magnetic field
  3.    weak magnetic field
  4.    no magnetic field
 Discuss Question
Answer: Option C. -> weak magnetic field
Answer: (c).weak magnetic field

Latest Videos

Latest Test Papers