Q.1
A coil is designed for high Q performance at a rated voltage and a specified frequency. If the frequency is made twice the original and the coil is operated at the same rated voltage, then the Q factor will be affected as ____________
Questionnetwork-theory-questions-answers1.jpg
  • a) Q is halved
  • b) Q remains unchanged
  • c) Q is doubled
  • d) Q increases or decreases but magnitude cannot be measured
Q.2
A coil is designed for high Q performance at a rated voltage and a specified frequency. If the frequency is made twice the original and the coil is operated at the same rated voltage, then the active power P will be affected as ____________
  • a) P is halved
  • b) P remains unchanged
  • c) P is doubled
  • d) P decreases 4 times
Q.3
The effective inductance of the circuit across the terminals A, B is _______________
  • a) 9 H
  • b) 21 H
  • c) 11 H
  • d) 6 H
Q.4
A (A/7A),Hz current transformer has a primary bar. The secondary has a pure resistance of 1 Ω. It also draws a current of 5 A. The magnetic core requiresAT for magnetization. Find the percentage ratio error.
Questionnetwork-theory-questions-answers4.jpg
  • a) 10.56
  • b) -28.57
  • c) 11.80
  • d) -11.80
Q.5
The CT supplies current to the current coil of a wattmeter power factor meter, energy meter and, an ammeter. These are connected as?
Questionnetwork-theory-questions-answers5.jpg
  • a) All coils in parallel
  • b) All coils in series
  • c) Series-parallel connection with two in each arm
  • d) Series-parallel connection with one in each arm
Q.6
The average power absorbed by an impedance Z =– jΩ when a voltage V = 120∠is applied is _____________
  • a) 35
  • b) 37.24
  • c) 45
  • d) 50.25
Q.7
A moving iron ammeter produces a full-scale torque ofμN-m with a deflection ofat a current ofA. the rate of change of self-inductance (μH/rad) of the instrument at full scale is?
  • a) 2.0 μH/rad
  • b) 4.8 μH/rad
  • c) 12.0 μH/rad
  • d) 114.6 μH/rad
Q.8
The relation between the Q factor of a coil measured by the Q Meter and the actual Q of the coil is _________
  • a) Equal to
  • b) Same but somewhat lesser than
  • c) Same but somewhat higher than
  • d) Not equal to
Q.9
The meter constant of a single-phase,V induction watt-meter isrev/kW-h. The speed of the meter disc for a current ofA at 0.8 power factor lagging will be?
  • a) 30.3 rpm
  • b) 25.02 rpm
  • c) 27.6 rpm
  • d) 33.1 rpm
0 h : 0 m : 1 s