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 ____________
- 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.
- 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?
- 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