Winding MCQ Quiz - Objective Question with Answer for Winding - Download Free PDF

• The given figure represents Simplex Winding. 
• In simplex winding, there is a single coil or set of coils that are connected in a straightforward series or parallel connection.
• From the figure, the conductors appear to be arranged in such a way that each phase winding is individually wound, making it a simplex configuration.
• The other options like duplex, triplex, or concentric winding refer to more complex winding arrangements where there are multiple parallel windings or differently spaced windings, which is not shown in this diagram.

Explanation: Types of winding :

1. Concentric Winding:

• In concentric windings, the coils are placed in layers, with each layer having a different radius, forming concentric circles.
• This type of winding is commonly used in transformers and electrical machines where insulation and cooling are critical.
• Concentric windings are known for their simplicity and ease of manufacturing.
   

2. Triplex Winding:

• Triplex winding involves three sets of windings arranged in a specific pattern.
• This type of winding is often used in specialized applications where three-phase power is required.
• It is less common in standard electrical machines compared to other winding types.
   

3. Duplex Winding:

• Duplex winding consists of two sets of windings that are typically used for redundancy or to handle higher currents.
• This type of winding is used in applications where reliability and performance are critical.
• Duplex windings are more complex than simplex windings but offer better efficiency and reliability.
   

4. Simplex Winding:

• Simplex winding is the most basic form of winding, with a single set of windings.
• It is commonly used in small electrical machines and devices where simplicity and cost-effectiveness are essential.
• Simplex windings are easy to manufacture and maintain.

The correct answer is option 4): (Lap coiling)

Concept:

Lap winding: In lap winding, the number of parallel paths (A) is the same as the number of brushes and poles This winding is mainly used for low voltage and high current applications

These windings are mainly linked for providing numerous parallel lanes for armature current.

Due to this reason, this type of winding is used in dc generators, and it requires some pairs of brushes and poles.

In this type of winding, the final end of the first coil is associated with a commutator section and to the first end of the closest coil is located beneath the similar pole till every coil have been associated.

Wave winding: In wave winding, the number of parallel paths is two This winding is mainly used for high voltage and low current applications

The correct answer is option 4): (Multiplex wave winding)

Concept:

In a wave winding,

The end of one coil is connected to the start of another coil of the same polarity.

The coil side (X – Y) proceeds forward around the armature to another coil side and goes on successively passing through the North and South poles until it returns to a conductor (X1-Y1) lying under the starting pole.

Three or more Unidirectional wave coils connected in parallel are called multiplex Wave Winding.

It is a type of armature winding with more than two even parallel paths.

where 

A = parallel path

m = plex

For wave winding, No of parallel path will be

A = 2m

 if m = 2

It is a duplex wave winding

if m = 3

It is a Triplex wave winding

The correct answer is option 1): (pole pitch)

Concept:

Pole Pitch:

It is the angular distance between the two adjacent poles. This distance is measured in terms of armature slots or armature conductors that come between two adjacent pole centers.

This is naturally equal to the total number of armature slots divided by the number of poles in the machine

Additional Information

• The number of slots per pole per phase determines how the winding layout is arranged. It is also disclosing information about the winding factor and its harmonics
• Coil span or coil pitch is said to be the distance between the two sides of a coil.

The correct answer is option 2): Average pitch

Concept:

Pole pitch: The distance which is measured  on the circumference of the armature from the one pole's centre  to the next pole's centre 

Back pitch (Y_B ): The distance between the top and bottom coil sides of a coil measured around the back of armature is called back pitch.

Average Pitch (Y_A):

Y_A = \(Y_B + Y_F\over 2\)

The half of the sum of the front pitch and the back pitch called as Average Pitch.

The correct answer is option 4): (Lap coiling)

Concept:

Lap winding: In lap winding, the number of parallel paths (A) is the same as the number of brushes and poles This winding is mainly used for low voltage and high current applications

These windings are mainly linked for providing numerous parallel lanes for armature current.

Due to this reason, this type of winding is used in dc generators, and it requires some pairs of brushes and poles.

In this type of winding, the final end of the first coil is associated with a commutator section and to the first end of the closest coil is located beneath the similar pole till every coil have been associated.

Wave winding: In wave winding, the number of parallel paths is two This winding is mainly used for high voltage and low current applications

The correct answer is option 2):(1/2 of the number of slots)

Concept:

Single layer winding:

• When each side of a coil occupies a slot completely without any other coil lying on top of it and the number of coils equals half the number of slots, the winding is known as single layer winding
• Single- layer windings have coils wrapped every two teeth, while in the double layer windings coils are wound on each tooth.
• In single-level winding, the required number of coils is  1/2 of the number of slots

The correct answer is option 3):(Half coil connection)

Concept:

• Half coil winding is that type of  winding where the number of coils per phase is equivalent to half the number of poles in the machines
• In a winding, if the number of coils per phase is equal to the number of pairs of poles, it is called  Half coil connection

• In this type each coil may have two times the number of turns of a whole coil winding or two coils within a north or South Pole of the latter type might be connected in series and taped jointly to form one coil.
• The major variation among the full coil and half coil windings is in the method of building the end connections for the coils

The correct answer is option 1): (pole pitch)

Concept:

Pole Pitch:

It is the angular distance between the two adjacent poles. This distance is measured in terms of armature slots or armature conductors that come between two adjacent pole centers.

This is naturally equal to the total number of armature slots divided by the number of poles in the machine

Additional Information

• The number of slots per pole per phase determines how the winding layout is arranged. It is also disclosing information about the winding factor and its harmonics
• Coil span or coil pitch is said to be the distance between the two sides of a coil.

The correct answer is option 3):(Skew winding)

Concept:

•  The slots for the placement of conductors are not made exactly in parallel with the rotor shaft.
• A slight angle is maintained which means the rotor slots are made at some angle with the rotor shaft.
• This is called the Skewing of the rotor or Skewed Rotor.
• The coil sides of the winding are unequal and this gives more space for thermal radiation as shown in the given figure. This type of winding is known as Skew winding
• 

The correct  answer is option 2):(Concentric winding)

Concentrated winding :

• Concentrated winding is employed where the number of slots on the armature is equal to the number of poles in the machine.
• This armature winding of the alternator gives maximum output voltage but not exactly sinusoidal.
• The most simple single-phase winding is shown below in the figure. Here, the number of poles = number of slots = number of coil sides.
• Here, one coil side is inside one slot under one pole, and the other coil side inside the other slot under the next pole. The emf induced in one coil side is added to that of the adjacent coil side.

• The above given picture is concentric winding

The correct answer is option 1):(Total number of coils / number of phases)

Concept:

• Total number of coils per phase = (Total number of coils / Number of phases)
• If the number of slots/pole/phase is an integer, the winding is called integer-slot winding. If the number of slots/pole/phase is fractional and superior to 1, the winding is called fractional-slot winding.
• If the number of slots/pole/phase is fractional and inferior to 1, the winding is called concentrated winding. Windings with the same number of slots/pole/phase have the same winding factor.
• Their winding layouts consist of the same basic sequence repeated by the number of winding symmetries (or machine periodicity).

The correct answer is option 4):  Stepped former is not required.

Concept: 

• Concentrated winding is employed where the number of slots on the armature is equal to the number of poles in the machine.
• This armature winding of the alternator gives maximum output voltage but is not exactly sinusoidal.
• The most simple single-phase winding is shown below in the figure. Here,

• The number of poles = number of slots = number of coil sides. Here, one coil side is inside one slot under one pole, and the other coil side is inside the other slot under the next pole.
• The stepped former is required.
• The coil arms do not have interlocking, so the coiling can be done by machine, which leads to faster production.
• During coiling, there is no need to lift the coil arms for introversion.
• The emf induced in one coil side is added to that of the adjacent coil side.
• Hence  option 4 is incorrect.

The correct answer is option 4): (Coil-3)

Concept:

Duplex Lap Winding

A winding in which the number of parallel paths between the brushes is twice the number of poles is called duplex lap winding.

In duplex lap winding, the coil-1 end leads is connected with an  coil 3 initial leads as in figure

The correct answer is option 2):  5 slots 

Concept:

• Coil span (also known as coil pitch) is defined as the peripheral distance between two sides of a coil, measured in terms of the number of armature slots between them.
• It means one side of the coil in a particular slot, after how many conjugative slots, the other side of the same coil is placed on the armature. This number is known as the coil span

Pole pitch = \(No\:of\: slots \over No \: of \: poles\)

Coil span = pole pitch ,In full pitch coil

Coil span < pole pitch in short pitch coil

Calculation

Given that,

 Number of slot = 22

Number of slot  per pole = 5.5 = 5(round off ) 

Coil span = 5 slot

One side of the coil will be 1st slot means the next side of the coil will be at the fifth slot (assume that the coil is short pitch)