Q.1
AHz, bar primary CT has a secondary withturns. The secondary supplies 7 A current into a purely resistive burden of 2 Ω. The magnetizing ampere-turns areThe phase angle is?
  • a) 3.1°
  • b) 85.4°
  • c) 94.6°
  • d) 175.4°
Q.2
AHz, bar primary CT has a secondary withturns. The secondary supplies 5 A current into a purely resistive burden of 1 Ω. The magnetizing ampere-turns areWhat is the ratio error at full load, if the iron loss is 1.5 W and magnetizing mmf isA?
  • a) Zero
  • b) 45 μWb
  • c) 25.5 μWb
  • d) 100 μWb
Q.3
A 1000/5 A,Hz correct transformer has a secondary burden comprising a non-inductance of 1.6Ω. The flux in the core at full load is?
  • a) 160 μWb
  • b) 180 μWb
  • c) 200 μWb
  • d) 150 μWb
Q.4
A 1000/5 A,Hz correct transformer has a secondary burden comprising a non-inductance of 2Ω. What is the ratio error, if the iron loss is 3 W and magnetizing mmf isA?
  • a) 4%
  • b) 5.7%
  • c) 3.6%
  • d) 4.8%
Q.5
A 200/1 Current Transformer (CT) is wound withturns on the secondary on a toroidal core. When it carries a current ofA on the primary, the ratio is found to be -0.5%. If the number of secondary turns is reduced bythe new ratio error (in %) will be?
  • a) 0.0
  • b) -0.5
  • c) -1.0
  • d) -2.0
Q.6
A (A/ 7A),Hz current transformer has a primary bar. The secondary burden is a pure resistance of 1 Ω and it 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.7
The observation when the secondary winding of a current transformer is open-circuited is?
  • a) The whole of the primary current produces a large value of flux in the core thereby producing a large voltage in the secondary winding
  • b) The large voltage may act as a safety hazard for the operators and many even raptures the insulation
  • c) When the large magnetizing force is taken off, it leaves a large value of residual magnetism
  • d) When the large magnetizing force is taken off, it leaves a small value of residual magnetism
Q.8
Usually a CT has ____________
  • a) Power overload capacity than PT
  • b) The same overload capacity as a PT
  • c) A higher overload capacity than a PT
  • d) No overload capacity
Q.9
A PT is a device which is ___________
  • c) Electromagnetically coupled
  • a) Electrostatically coupled
  • b) Electrically coupled
  • d) Conductively coupled
Q.10
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
0 h : 0 m : 1 s