The CT supplies current to the current coil of a wattmeter power factor meter, energy meter and, an ammeter. These are connected as?

Series-parallel connection with two in each arm

Series-parallel connection with one in each arm

Usually a CT has ____________

Power overload capacity than PT

The same overload capacity as a PT

A higher overload capacity than a PT

When the large magnetizing force is taken off, it leaves a large value of residual magnetism

The whole of the primary current produces a large value of flux in the core thereby producing a large voltage in the secondary winding

The large voltage may act as a safety hazard for the operators and many even raptures the insulation

When the large magnetizing force is taken off, it leaves a large value of residual magnetism

When the large magnetizing force is taken off, it leaves a small value of residual magnetism

1.	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
Answer» C. Series-parallel connection with two in each arm

2.	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
Answer» D. No overload capacity

3.	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
Answer» C. When the large magnetizing force is taken off, it leaves a large value of residual magnetism

4.	A (350 A/ 7A), 50 Hz current transformer has a primary bar. The secondary burden is a pure resistance of 1 and it draws a current of 5 A. The magnetic core requires 350 AT for magnetization. Find the percentage ratio error.
A.	10.56
B.	-28.57
C.	11.80
D.	-11.80
Answer» C. 11.80

5.	A 200/1 Current Transformer (CT) is wound with 400 turns on the secondary on a toroidal core. When it carries a current of 180 A on the primary, the ratio is found to be -0.5%. If the number of secondary turns is reduced by 1, the new ratio error (in %) will be?
A.	0.0
B.	-0.5
C.	-1.0
D.	-2.0
Answer» D. -2.0

6.	A 1000/5 A, 50 Hz correct transformer has a secondary burden comprising a non-inductance of 2 . What is the ratio error, if the iron loss is 3 W and magnetizing mmf is 250 A?
A.	4%
B.	5.7%
C.	3.6%
D.	4.8%
Answer» C. 3.6%

7.	A 1000/5 A, 50 Hz correct transformer has a secondary burden comprising a non-inductance of 1.6 . The flux in the core at full load is?
A.	160 Wb
B.	180 Wb
C.	200 Wb
D.	150 Wb
Answer» C. 200 Wb

8.	A 50 Hz, bar primary CT has a secondary with 500 turns. The secondary supplies 5 A current into a purely resistive burden of 1 . The magnetizing ampere-turns are 200. What is the ratio error at full load, if the iron loss is 1.5 W and magnetizing mmf is 100 A?
A.	Zero
B.	45 Wb
C.	25.5 Wb
D.	100 Wb
Answer» C. 25.5 Wb

9.	A 50 Hz, bar primary CT has a secondary with 800 turns. The secondary supplies 7 A current into a purely resistive burden of 2 . The magnetizing ampere-turns are 300. The phase angle is?
A.	3.1
B.	85.4
C.	94.6
D.	175.4
Answer» B. 85.4