This set of Design of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Current Transformers Construction”.
1. How many types are the current transformers classified into?
a) 2
b) 3
c) 4
d) 5
View Answer
Explanation: The current transformers are classified into 2 types. They are wound type and bar type.
2. What is the wound type current transformer?
a) primary winding having one full turn wound on core
b) primary winding having more than one full turn wound on core
c) secondary winding having one full turn wound on core
d) secondary winding having more than one full turn wound on core
View Answer
Explanation: The wound type current transformer is one of the classifications of the current transformers. The primary winding has more than one full turn wound on core.
3. What is the bar type current transformer?
a) primary winding consists of a rod of suitable size and material
b) primary winding consists of a bar of suitable size and material
c) secondary winding consists of a rod of suitable size and material
d) secondary winding consists of a bar of suitable size and material
View Answer
Explanation: The bar type current transformer is one of the classifications of the current transformers. In bar type winding, primary winding consists of a bar of suitable size and material.
4. How many commonly used shapes of current transformer are present?
a) 1
b) 2
c) 3
d) 4
View Answer
Explanation: The current transformers consist of 3 commonly used shapes. They are stadium, circular, rectangular orifices.
5. What material is made use of for the lamination in the current transformer?
a) cold rolled steels
b) hot rolled steels
c) copper
d) hot iron
View Answer
Explanation: The current transformer consists of stacks of laminations. The lamination used in the current transformer is hot rolled steel.
6. What is the insulation material used in the current transformer?
a) elephantide
b) presspahn
c) elephantide and presspahn
d) elephantide or presspahn
View Answer
Explanation: The insulation in current transformer is by means of end collars and circumferential wraps. The insulation material used in elephantide or presspahn.
7. What is the additional usage of the presspahn material used as insulation material?
a) lamination
b) to reduce the losses
c) to protect secondary winding conductor from mechanical damage
d) to protect secondary winding conductor from electrical damage
View Answer
Explanation: The presspahn is used as insulating material in the current transformer. In addition to that the presspahn is also used to protect the secondary winding conductor from mechanical damage.
8. What is the other name of the ring type current transformer?
a) brush transformer
b) cloud transformer
c) circular transformer
d) bushing transformer
View Answer
Explanation: The ring type current transformer is one type of current transformer. It is also known as the bushing transformer.
9. How many faces are present in the split core current transformer?
a) 2
b) 3
c) 4
d) 5
View Answer
Explanation: The split core transformer consists of a split core. The split half consists of 2 finely grounded or lapped gap faces.
10. The current transformers are assembled on to the secondary conductors “on site” for either permanent or temporary duty.
a) true
b) false
View Answer
Explanation: The current transformers are assembled on to the primary conductors. They are assembled “on site” for the permanent or temporary duty.
11. What is the insulation material on the primary conductor?
a) bakelized paper tube
b) resin
c) bakelized paper tube and resin
d) bakelized paper tube or resin
View Answer
Explanation: The insulation material on the primary conductors is generally made up of the bakelized paper tube. It can also be made use of resin directly moulded on the bar.
12. How is the reluctance of the interleaved corner related with the magnetizing current?
a) reluctance of the interleaved corner is directly proportional to the magnetizing current
b) reluctance of the interleaved corner is indirectly proportional to the magnetizing current
c) reluctance of the interleaved corner is directly proportional to the square of the magnetizing current
d) reluctance of the interleaved corner is indirectly proportional to the square of the magnetizing current
View Answer
Explanation: The reluctance of the interleaved corner is directly proportional to the magnetizing current. As the reluctance is being reduced it in turn reduces the magnetizing current.
13. To reduce the peak voltage between layers, the secondary winding is being sectionalized.
a) true
b) false
View Answer
Explanation: The large number of secondary turns requiring more than 1 winding layer, the secondary winding is sectionalized. This is because to reduce the peak voltage between layers.
Sanfoundry Global Education & Learning Series – Design of Electrical Machines.
To practice all areas of Design of Electrical Machines, here is complete set of 1000+ Multiple Choice Questions and Answers.
If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]
