How Can Birds Sit Safely on Power Lines?

 

Why Can Birds Sit Safely on Power Lines?

You must have seen the birds sitting on Electric wires and then you must have wondered how these birds are sitting so comfortably on Electric wires and question arises that why they don't feel the Electric shock? 

Because when we accidentally touch the open wire we get a shock . Usually overhead transmission lines are not insulated when bird's should feel electrical shock. But they don't ! It's not because the birds have some sort of superpower.

 To know the reason,we have to overlook some of the concepts of electricity .

(1) Electricity always flows through a path of least resistance :

The power lines through which the Electric current flows ,are usually made up of aluminium.

 Aluminium offers least resistance and it is good Conductor of electricity . Hence, electricity ignores the birds ( as they having higher Resistance than aluminium ) and flows through the power lines and birds don't get shocked .

(2) Electricity flows higher potential to lower potential :

The power lines run at different potentials. If birds sitted on the Same power line ,then they are at same potential . So, birds don't get shocked. 

However, when bird touches ,two cables with different potentials at same time then the electricity flows through bird to go other to other cable with lower potential and bird get shocked.

(3) Electricity flows only when there is closed loop/ path :

Typically larger raptors like eagles, hawks, owls ,etc.

 This birds will perch on an electrical pole/ tower ,then stretch out a wiring brush against a power line.That completes the circuit between the power line and the pole / tower which leads to ground .

 

Now, the another question arises ...

           Will man gets shocked when he touches the power lines ?

Answer is NO . Because man having no contact with ground or other phase wires or neutral wires touches power lines 

Hence, electricity ignores the man ( as he having higher Resistance than aluminium ) and flows through the power lines.

But If man having contact with ground or neutral or another phase touches the power line that completes the circuit between the power line and the pole / tower  which

 leads to ground . Hence, he will feel high voltage shock and this even cause death . It's dangerous !

Hope this helps you. Thank you ❤️

why aluminium is used in Transmission Lines | material used in Transmission Lines

Transmission lines: 

 Definition transmission Line helps in the transfer of electricity from a power plant or power station to the various substations.

 Transmission line is an important part of power system. The cost and life of transmission line majorly depend on the material of conductor for transmission line.The most extensively used material is aluminium. ACSR conductor is most popular material used for high voltage overhead transmission lines. 

Required Properties of Conductor which is used in Transmission Line

>High conductivity

>High tensile strength

>Light weight

>High resistance to corrosion in whether conditions

>High thermal stability

>Low coefficient of thermal expansion

>Low cost

Conductivity :

As we all know that we select any conductor by looking at conductivity of conductor .Meaning we always use the wire inside which the resistance is minimum so that current can flow easily.

 So if we talk about the best conductive material of electricity, then silver comes first in the number. (Silver is a material in which the current passes easily).

                             Silver

Thee conductivity of silver is said to be the best.

            Metal                    Resistivity 

                                          (10^- 6 ohm-cm )

         1.silver                      1.55

         2.copper                  1.7

         3.gold                      2.2     

         4.aluminium            2.7 

 After this, the name of copper comes on the second number, after copper, gold comes on the third number.

 And if we talk about aluminum, then it comes at number 4 in this list.

 now you know which material is the best conductor. But here we have a problem that the silver and gold are very worthy. So it is completely impossible to use the wire of both these materials.

                                    Gold

 Because a kilogram of silver costs around 40,000 rupees and if we talk about gold, then it is about 40,00,000 kg. Which is much more expensive.

 So now we have only two materials left:

 <1>Copper 

                                  Copper

<2> Aluminum 

 

                                 Aluminum 

Cost:

The cost of both these materials is very low. You get 1 kg of copper for 500 rupees, while the same aluminum gets 1 kilogram for just 100 rupees (generally).

 Cost wise (because of the price) -1 Kg of copper costs around 500 rupees, while aluminum we get only 100 rupees a kilogram. So even if we double the thickness of this aluminum wire, the price of 2 kg of aluminum will be only Rs 200, which is about 60% less than copper.

Difference between Copper and Aluminum: 

 Resistivity- 

Copper is a better material than aluminum in terms of resistance. Copper resistance is 60% less than aluminum.

 For example, if we have copper and aluminum conductors of exactly the same size, if the resistance of copper wire is 1 ohm, then the resistance of aluminum wire of this size will be 1.6 ohm. So we came to know that the resistance of copper is low.

 :There is a rule of resistance that if we enlarge the size of the material, we will make it thicker. The resistance then decreases. (R = pl /A )

 :If we do this with aluminum, if we double the aluminum wire, the resistance of the wire will be reduced from 1.6 to 0.8.

 Weight - 

The second major difference after this is on the weight of these two. And this point is very important for wire selection of transmission line. Because we all know if our wire will have more weight. So at that time we also have to install towers of high power so that it can withstand the wire of high weight.

:This means that the difference in the weight of the wire directly comes at the cost of the tower.

:The weight of copper is more than aluminum.

:For example, if a copper wire weighs 1 kg, the aluminum wire of exactly the same size will weigh only 0.33 KG.

: So if we use aluminum, the cost of building transmission line towers will come down, because aluminum wire is lighter in weight than copper.

 Long life - 

we do not use insulation on the transmission line wire. So if we use copper wire outdoors without insulation, then at this time we have to give a lot of maintenance to the copper wire.

                               Rust - corrosion

Corrosion takes place very quickly over copper. And if we use the same aluminum, then there is no problem of rusting in it. So if we use aluminum instead of copper, it will be maintenance free and the life of this wire will be more than copper wire.

Because of above advantages over copper aluminium is used in Transmission Lines.

Why cuts /splits on the plug ?

 Today we will know the correct answer to why there are cuts on the pulgs. Before that you should know that which type of  pulgs have cuts ? All types of plugs have not cuts /splits . 

Plug :

Plug is a device for making an electrical connection between an appliance and the mains, consisting of an insulated casing with metal pins that fit into holes in a socket.

  The cuts are only in plugs which are made from brass material.

Why cuts are only in plugs made from brass material?

Brass is a good conductor of electricity . But if high amount of current passed through it , it get expanded . 

Expansion ➡️ (depends on) current

(The Pins are made of brass sometimes coated with nickel to avoid the common rust. Therefore white in colour.)

Brass has high coefficient of thermal expansion. So if the temperature of the pins go up(for any reason), it would be very difficult to pull out the plug because inside the socket ,the plastic sockets can get jammed due to thermal expansion.

To control this situation,the cuts are made to reduce Area of plug . We know the inverse relation of resistance and area .

R= p( l / A )

      p : Resistivity 

       l : length of Conductor

      A : Area of Conductor

        

 Hence as resistance increases current flow decreases . As current decreases , the expansion also decreases. 

Expansion ➡️ (depends on) current

What is brass ? 

Brass is an alloy of copper and zinc, in proportions which can be varied to achieve varying mechanical and electrical properties.It is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure.

Ideal transformer on no- load

 An ideal transformer is a nonexistent transformer which has 

- no copper loss (no winding obstruction) 

- no iron loss 

- no leakage flux

All in all, an ideal transformer gives yield power precisely equivalent to the info power. The proficiency of an ideal transformer is 100% . In reality, it is difficult to have such a transformer by and by, yet ideal transformer model makes issues simpler. 

Attributes Of Ideal Transformer 

Zero winding obstruction (resistance): It is expected to be that, opposition of essential just as optional twisting of an ideal transformer is zero. That is, both the curls are simply inductive in nature. 

Limitless permeability: Higher the permeability, lesser the mmf needed for motion foundation. That implies, if permeability is high, less charging current is needed to polarize the transformer.

No leakage current: Leakage transition is a piece of attractive motion which doesn't get connected with optional winding. In an ideal transformer, it is accepted that whole measure of motion get connected with optional winding (that is, no spillage motion). 

100% effectiveness: An ideal transformer doesn't have any losses like hysteresis loss, leakage current and so on In this way, the output power of ideal transformer is equal to the input power. Thus, 100% effectiveness. 

Ideal Transformer Equations 

The properties which we have talked about in the above are not relevant to the functional transformer. In an ideal sort transformer, the o/p power is equivalent to the I/p power. Accordingly, there is no deficiency of force. 

E2*I2*CosΦ = E1*I1*CosΦ in any case E2*I2 = E1*I1 

E2/E1 = I2/I1 

In this way, the transformation proportion condition is appeared beneath. 

V2/V1= E2/E1 = N2/N1 = I1/I2 =K 

The flows of essential and optional are contrarily relative to their separate turns. 

Phasor Diagram of Ideal Transformer 

Think about an ideal transformer on no heap as demonstrated in the figure. The inventory voltage is V1 and as it is a no heap the auxiliary current I2 = 0 

The essential draws a current I1 which is only important to create motion in the center. As it is polarizing the center, it is called charging current signified as Im. As the transformer is ideal, the winding reactance is zero and it is absolutely inductive in nature. The polarizing current is exceptionally little and slacks V1 by 90° as the winding is absolutely inductive. This Im produces a substituting motion Φ which is in stage with Im. 

The motion joins with bith the winding delivering the initiated emf E1 and E2, in the essential and auxiliary windings separately. As per Lenz's law, the instigated emf goes against the reason creating it which is supply voltage V1. Thus E1 is in antiphase with V1 yet equivalent in extent. The instigated emf E2 likewise goes against V1 henceforth in antiphase with V1 however its size relies upon N2. Hence E1 and E2 are in stage. 

The phasor graph for the ideal transformer on no heap is appeared in the figure. 

It very well may be seen that motion is reference. Im produces motion thus in stage with phi. V1 drives Im by 90 degree as winding is simply inductive so current needs to slack voltage by 90 degree. 

E1 and E2 are in stage and both restricting stock voltage V1. 

The force contribution to the transformer is V1 I1 cos (Angle somewhere in the range of V1 and I1) for example zero. 

Benefits of ideal transformer:

The advantages of the ideal transformer include the following.

•There are no losses like hysteresis, eddy, and copper. Losses = 0.

•Voltage & current ratios are perfectly based on the no. of turns of the coil.

•There is no leakage flux

•Perfect linearity

•No stray inductance & capacitance 

Difference Between core type and shell type transformer

Difference Between core type and shell type transformer

(1) Core type transformer the core surrounds the windings whereas Shell type transformer the winding surrounds the core of the transformer.

                  Core type transformer

                         Shell type transformer

(2) core type transformer the lamination is cut in L-shape whereas, in shell type transformer, the laminations are cut in the E and L shape.

(3)The cross-section area of the core type transformer is rectangular shape, whereas the cross-section area of the shell type transformer is square shape, cruciform two slipped, or three stepped in shapes.

(4)The core type transformer requires more amount of copper conductor as compared to shell type transformer because in core type transformer the winding is placed on the separate limbs or legs.

(5) The core type transformer affords better cooling surface for the windings than the shell type core . 

(6) The core type transformer is also called cylindrical or core winding transformer because their windings are arranged as the concentric coil. In shell type transformer, the low voltage winding and the high voltage winding are put in the form of the sandwich, and hence it is called the sandwich or disc winding transformer.

(7) Core type transformer works on good power factor whereas shell type transformer works on poor power factor .

(8)The core type transformer has two limbs, whereas the shell type transformer has three limbs.

(9)The mechanical strength of the core type transformer is low as compared to shell type transformer because the shell type transformer has bracings.

(10)The core type transformer required less insulation as compared to shell type transformer because shell type transformer has three limbs.

(11) In core type transformer the flux is equally distributed to the side limb of the transformer whereas, in shell type transformer, the central limb carries the whole of the flux and the side limbs carry the half of the flux.

(12)In core type transformer both the primary and the secondary windings are placed on the side limbs whereas, in shell type transformer, the windings are placed on the central limbs of the transformer.

(13) The core type transformer has two magnetic circuits whereas the shell type transformer has one magnetic circuit.

(14) The losses in a core type transformer are more as compared to shell type transformer because the core type transformer consists two magnetic circuits.

(15)The output of the core type transformer is less because it has more losses as compared to the shell-type transformer.

I hope this helps you. Thank you ❤️.

why transmission is done at high voltage

 

Why transmission is done at high voltage

     Whenever a transmission  word comes into our mind,the numbers 132 kV,33 kV ,66 kV,etc., floats infront of our eyes. 

       Our household appliances like fan, refrigerator works efficiently on 230 V. Even for industrial purpose, we need 440V (generally). 

      Then why transmission is done at high voltage? What is need of this extra high voltage?

Now friends ,you must know we don't generate high voltage at Generating station. Usually we generate the power of 11 kV voltage.

So friends ,to transmit high voltage there is need of the transformer to convert 11 kV (generating voltage) to higher voltage. Now this is a step up transformer, it is worth a lot. Because of use of transformer, our cost of transmission increases .

Then why we use high voltage for transmission? Is there any advantage ? Let's see .

 Advantages of high line voltage: 

(1)low voltage drop:   

Power is transmitted over large distances to load centers with the help of conductors. We know , resistance increases with increase in length of conductor( prefer formula) .      

  

               R= p l /A                 

Hence, the voltage drop across conductor also increases .

 As transmission line voltage is high , voltage drop across line is decreased.

(2)low cost: 

As we increase /step up voltage by using transformer , current decrease with respect to increase in voltage

 (as per low of energy conservation)

        We know ,   power                         

               P = constant 

    Also , P= V*I

Since current decreases area of material (A) also decreases 

              I = V / R       ....  I α 1/R

             R = p l / A     ....  R α 1/A

Hence,

            I α A 

 

Therefore it requires less material . Effectively low cost of conductors.

(3)less power loss:

Increase in voltage reduces the power loss. As voltage drop is less for high voltage as compared to low voltage ,the power loss decreases and we have better voltage regulation .

 Disadvantages of high line voltage

  From the above discussion, it is advisable to use the highest possible voltage for transmission of power in a bid to save conductor material. However, it must be realised that high transmission voltage results in

(1) The increased cost of insulating conductors : 

      As the voltage tension increases on wire,there is need to increase insulation. But for transmission lines we don't use insulation . 

(2) The increased cost of transformers, switchgear and other terminal apparatus (of high voltage rating)

(3) Tower height increase : in order to minimise line - ground fault . 

(4) Increase corona effect (corona discharge)

 I hope this helps you. Thank you ❤️.

Why does positive charge attracts negative charge?

 What is charge ?

All physical objects are made up of atoms. Inside an atom there are protons, electrons and neutrons. The protons are positively charged, the electrons are negatively charged, and the neutrons are neutral.

Therefore, all things are made up of charges. Opposite charges attract each other (negative positive or positive negative). Like charges repel each other (positive positive or negative negative).

Why does positive charge attracts negative charge? 

It is the tendancy of every body to have minimum electrical potential  i.e .to obtain   zero potential .  A positive  charge means a deficit of electrons while the negative charge indicates excess of electrons . Consequently, the positive and negative charges attract each other to have minimum electrical potential. 

I hope this helps you. Thank you ❤️.

( Electron + proton = Neutron)

Parameters of a transmission lines|resistance|inductance|capacitance

 A transmission line is used to the transmit of electrical power from generating substation to the various distribution units. Transmission lines transmits the high voltage and current from one end to another. The transmission line is made up of a conductor of uniform cross-section along the line. Air work as an insulating medium or dielectric medium between the conductors.

For safety purpose, the distance between the line and ground is kept more. The electrical tower is used to give support to the conductors of the transmission line.Tower are made up of steel which provides high strength to the conductor. 

Parameters of transmission line

The performance of transmission line depends on the parameters of the transmission line. The transmission line has majorly four parameters -

 resistance

 inductance

 capacitance  

 shunt conductance. 

   These parameters are uniformly distributed along the line. Hence, also called the distributed parameter of the transmission line.

• Resistance : 

Resistance is the opposition of line conductors to current flow. Every material have the property to oppose the flow of current. The resistance is distributed uniformly along the whole length of the lines as  shown  in    figure. However , performance of a transmission line can be analysed conventionally if distributed resistance is considered as lumped as shown in figure.

• Inductance:

Electric power is transmitted through the transmission lines with alternating  high voltage and current . High  valued (AC) alternating current while flowing through conductor sets up alternating magnetic flux of high strength. This flux linkage with other adjecent conductors parallel to main conductor .                                                        The  inductance is also uniformly distributed along the length of conductor. 

• Capacitance: 

We know that any two conductors separated by insulating material constitute a capacitor.                                      

 As any two conductors of an overhead transmission lines are separated by air which acts as an insulation , therefore ,  capacitance exists between any two over- head line conductors . The capacitance between conductors is the change per unit potential difference.

The capacitance is uniformly distributed along the whole length of the line ( uniform series of capacitors connected between the conductors ). This results is that a current flows between the conductors known as charging current and flows in the line even it is open - circuited . 

These parameters affects the voltage drop along the line as well as the efficiency and power factor of the line. 

Why transmission lines are not insulated?

 Why transmission lines are not insulated?

To answer the question, we first overlook the benefits of

 insulation .

Insulation : 

It is the process in which wire is covered by an insulated material (bad Conductor of electricity) 

 Let's see why there is advantages insulation.

There are various reasons for providing insulation:

   (1) leakage current 

If wires are connected to ground then there is  flow of leakage current .To avoid this we give insulation to the wire 

   (2) to separate two  different conductors :

 If two different conductors ( or two different phase )

 comes in contact with each other there is chances for an accidents(short circuit)

   (3) to protect it from environment : 

There are some moisture content in air /environment

 which will damage the wire by producing rust on it.

   (4) protection against electrical shock :

If human or animal touches the live wires there are major chances for electrical shock sometimes   death also.  

  For protection purpose we use insulation.

   (5) mechanical strength:

Insulation provides mechanical strength to the wires .

Instead of so many advantages we don't use insulated lines for transmission. If we look over the transmission lines we will find that:

  (1) leakage current: 

As transmission lines and ground are not connected , since transmission.  

lines are fixed with high height from the ground,the leakage current will not produce . 

   (2) to separate two different conductors : 

Already the two  transmission lines (phases)

 are separated by a definite distance there is no need for insulation.

   (3) to protect it from environment :

Transmission lines are made up of ACSR (Aluminium

 Conductor Steel Reinforced). And aluminium resist rusting .

   (4) protection against electrical shock :

As the height of transmission tower and transmission line is very high such that

 human or animals can't reach so there is no chances for accidents.

   (5) mechanical strength: 

ACSR is a material having high mechanical strength .

Advantages of non-insulated transmission line: 

(1) low cost : 

     (I) for high voltage by transmission line there is need of  high insulation  

     (II) As insulation increases weight of lines also increases  . Therefore ,   tower cost  also increase.

(2) heat protection

       As transmission line are open there is direct contact between line and air .Due to this heated wire cools down easily. 

I hope this helps you. Thank you ❤️.

       

Transmission lines|distribution lines|Difference Between Transmission and Distribution Line

 

The transfer of an electric power from a power station(where power is generated) to consumer is known as electric supply system . 

An electric supply system consists of three major components viz. , the power station ,. the transmission lines and the distribution system . Electric power is produced at the power stations which are located at favourable places , generally these power stations are away from the consumers. We have to transmit it over large distances to load centers with the help of conductors known as transmission lines. Then power is distributed to large number of small (domestic) and big (industrial) consumers through a distribution network . 

The Difference Between Transmission and Distribution Line

 (1) Transmission Line helps in transfer of electricity from a power plant to the various substations whereas the distribution line carries electricity from the substation to the consumer’s end. i.e, to the domestic and commercial customers.

(2)Transmission line carries power or electricity in three phase supply system (three wires of phases r,y,b). Distribution system requires a single phase supply system for carrying electricity(three phases as well as neutral wire) .

(3)In transmission line ,neutral is not provided (to decrease cost of conductor) whereas in distribution line neutral is present.

(4) Transmission lines are not insulated (to minimize cost of insulation as high voltage requires high insulation) but distribution lines are insulated( for safety) .

(5) Transmission line carries electricity at a very high voltage (about 11000 volts ) whereas Distribution lines carries electricity at a very low and safe value level (about 220  or 440 volts.)

(5)Transmission line, conducts current at 69 kilo ampere or more, but distribution line conduct current at less than 69 kilo ampere.

(6)Distribution line are thin as compared to the transmission line.

I hope this helps you. Thank you ❤️.

Electric supply system| AC power supply scheme

 The conveyance of electric power from a power station to consumers premises is known as electric supply system . 

An electric supply system consists of three  principal  components  viz. , the  power station ,.  the    transmission lines  and the distribution   system . Electric power  is produced at the power stations which are located at favourable places , generally quite away from the consumers. It is then transmitted over large distances to load centers with the help of conductors known as transmission lines.  Finally , power  is distributed  to large number of small and big  consumers  through   a   distribution network . 

The electrical supply system can be broadly classified into(I) ac or dc system (II) overhead or underground system. 

AC power supply scheme: 

          In these supply system AC power is transmitted and distributed.

(1) Generating station:

 In Fig , G.S. represents the generating station where electric power is produced  by 3-phase alternators operating in parallel. The usual generation voltage is 11 kV. For economyin the transmission of electric power, the generation voltage (i.e., 11 kV) is stepped upto132 kV (or more) at the generating station with the help of 3-phase transformers.

Generally the primary transmission is carried at 66 kV, 132 kV, 220 kV or 400 kV.

(2) primary transmission:

 electric power at 132 kV is transmitted by  3-phase, 3-wire  overhead system  to  the  outskirts of    the  city . This forms the  primary transmission.

(3) secondary transmission:

  The primary transmission     line   terminates at   the receiving station (RS) which usually lies at the outskirts of the city. At the receiving station, the voltage is reduced to 33kV by step-down transformers. From this station, electric power is transmitted at 33kV by 3-phase, 3-wire overhead system to various sub-stations (SS) located at the strategic points in the city. This forms the secondary transmission.

(4) primary distribution:

 secondary transmission line terminates at the sub-station (SS) where voltage is reduced from 33 kV to 11kV, 3-phase, 3-wire. The 11 kV   lines   run  alog  the  important  road sides of  the  city.  This forms the primary distribution. It may be noted that big consumers (having demand more than 50 kW) are generally supplied power at 11 kV for further handling with their own sub-stations.

(5) secondary distribution: 

The electric power from primary distribution line (11 kV) is delivered to distribution sub-stations (DS). These sub-stations are located near the consumers’ localities and step down the voltage to 400 V, 3-phase, 4-wire for secondary distribution. The voltage between any two phases is 400 V and between any phase and neutral is 230 V. The single-phase residential lighting load is connected between any one phase and neutral, whereas 3-phase, 400 V motor load is connected across 3-phase lines directly. It may be worthwhile to mention here that secondary distribution system consists of feeders, distributors and service mains.

Feeder:

is a conductor which connects the substation to the area where power is to be distributed .   No tapping is taken to the consumers from feeders, so the current in it remains the same throughout .

Distributors:

Are Conductor from which numerous tapping from the pole mounted transformer is taken for the supply to the consumers The current through it is not constant because tapings are taken at various places along its length Voltage drop is main consideration

Service mains :

is a small cable which connects the distributor to the consumer's meter 

I hope this helps you. Thank you ❤️.

Suggested articles for you

Parameters of transmission lines

Difference Between Transmission and Distribution Line 

Why transmission lines are not insulated?

Why are electricity in forms of 11kV, 22kV, 33kV, 66kV, and 132kV transmitted in India?

Why are electricity in forms of 11kV, 22kV, 33kV, 66kV, and 132kV transmitted in India

 Electric supply system: definition

The transmission of electric power from a power station to consumers premises is known as electric supply system . 

An electric supply system consists of three major  components viz. , the power station ,the transmission lines and the distribution system . Electric power is produced at the power stations which are located at favourable places , generally quite away from the consumers. It is then transmitted over large distances  from substation to load with the help of conductors known as transmission lines. Finally , power is distributed to large number of consumers through a distribution system . 

    People cite  Form Factor a reason for so. Form Factor is defined as RMS (root mean square) Value to Average value of a given AC voltage and it is different for different waveforms.

 Now the commonly used AC waveform in transmission. A sine wave AC waveform has form factor of 1.11. So, the reason given is that the transmitted voltage of 10kV, 20kV, 60kV etc. is multiplied to this form factor to obtain such results which you described in the question like

For 10kV → 10 x 1.11 kV = 11.1 kV (It is approximately correct)

For 20kV → 20 x 1.11kV = 22.2 kV (It is approximately 22kV)

For 60kV → 60 x 1.11 kV= 66.6 kV (Error! it is 66kV)

Like that

120 x 1.11 kV = 133.2kV (A big error of about +1.2kV because it is 132kV as used)

As,there is huge difference (1kv) for 132 kv ,the form factor is not correct answer for the question.

(2)The generation companies tends to generate round figure high voltages like 10kV, 20kV, 60kV, 120kV etc. But this huge voltage need to be transmitted over huge distance. There is some voltage drop. This drop is 10%. That’s why generation companies add 10% more in their actual target which neutralizes the line losses and the receiving end gets the targeted result. 

Net voltage = Target Voltage + 10% of Target Voltage

→ 132kV = 120kV + 12kV (10% of 120kV)

→ 66kV = 60kV + 6kv (10 %of 60 kV)

But power loss depends on different factors :

• load type(resistive , inductive or capacitive. Losses of inductive and capacitive loads are greater than losses of resistive load)

•Load value (how much load we have)

•Length and number of lines (as length of line increases the voltage drop across the line because of increased resistance.For R phase we use one wire /two wires /three wires.)

•Location of load ( as length affects the voltage drop. )

•voltage level (losses deceases with increase in voltage and vice-versa.)

    From above factor ,our losses are dependent. So,we can't give accurate idea about losses ( they may be less than or greater than 10% because power loss depends on changing factors). Hence,the voltage drop is also not accurate answer .

More accurate and correct answer is : 

     *Technology available: which technology we are using 

     *Facilities available:which facilities are available 

     *Requirement: which type of load one wants to use (resistive, inductive or capacitive)

     *Components available. 

     From these points , engineers and developers stated the

       11kV, 22kV, 33kV, 66kV, and 132kV 

Voltage rating. 

Emf equation of transformer derivation

        When  a   alternating  or   sinusoidal voltage is applied to primary winding of transformer , flux sets up in the core is also alternating in nature.i.e the function of flux us sinusoidal (sine wave).

     Let,

        •ϕm be the maximum flux in Weber

        •f be the supply frequency in Hz

        •N1 is the number of turns in the primary winding

        •N2 is the number of turns in the secondary winding

Φ is the flux per turn in Weber

As shown in fig.,

      Flux increases from it's zero value to it's maximum value øm in one quarter of cycle i.e. in 1/4f seconds.

Average rate of change of flux is given by ,

                dø / dt

        =Øm/ [ 1/ 4f]

       =4*f*øm       Wb/s

Now, as the rate of change of flux per turn is known as emf in volts .

         Average emf / turn 

        =4*f*øm  volts   .........(1)

Form factor=RMS value/average value

                       =1.11 . 

 

Therefore, 

      RMS value of emf /turn 

      =1.11 * average value of emf /turn 

      =1.11* 4*f*øm           ...........from (1)

      =4.44*f*øm    volts   ............(2)

Now, RMS value of induced emf in whole primary winding,

        E1=RMS value of emf /turn *no. Of primary turns 

         E1=4.44*f*øm*N1       ...... (3)

Also RMS value of induced emf in whole secondary winding,

         E2=RMS value of emf /turn *no. Of secondary turns 

         E2=4.44*f*øm*N2       .......(4)

 

Equations (3) and (4) , are emf equations of transformer. 

• dividing equation (3) by equation (4)

     E1/E2 =N1/N2 

     From above equation ,we can say that magnitudes of E1 and E2 depend upon number of turns of primary and secondary respectively. 

    If N2>N1,then E2>E1 (or V2>V1) and we get a step-up transformer.

    If N2<N1,then E2<E1 (or V2<V1) and we get a step-down transformer. 

  Voltage transformation ratio :

     Dividing equation (4) by equation (3)

     E2/E1 =N2/N1 = K 

     K is called is voltage transformation ratio.

   

Transformer|working principle of transformer

   Transformer : definition   Transformer is a static device which transfers power from one circuit to another circuit.

So,why we call it as device?why not  machine? As we discussed , transformer is a static i.e do not have any moving parts in it.(DC motor is a machine as it has moving parts ).  Because of these ,transformer have high efficiency (no any frictional loss) and it requires less maintenance.            

    We can also say that Transformer is a device which steps up or step down the voltage rating.(for example -our equipment works on 215V but if given supply is 5V only. Then,we have to increase/step up the 5V supply to 215V for satisfactory operation.) 

        This device works on principal -Faradays law of electromagnetic induction.If one coil is connected to a source of an alternating voltage ,the current flows through the winding and produces an alternating flux in core . 

Transformer.  

  This flux links with secondary winding and produces mutual induced emf E2 in it. Also flux links with primary winding and produces  self induced emf E1.

     

    There are two types of windings.                                  

(1) primary winding - winding which is connected to source. (2)secondary winding -winding which is connected to load .They are insulated such that there is no any electrical contact between windings and core.

      

  Core is made up of silicon steel material which provides comman magnetic path for the windings. Windings are electrically separated but magnetically coupled because of this core.

Advantages of transformer: 

The benefits are referenced underneath: 

•Its advantage is controlling and balancing out the voltage transmission. 

•It doesn't need any beginning time. 

•It is exceptionally effective with less capital venture and low support. 

•They give disconnection to the ground. 

•There are no moving parts in Transformers thus, the frictional misfortunes are zero. 

Drawbacks of Transformer 

There are a few downsides in the exhibition of Transformers. Some of them are referenced beneath. 

•Due to its material in the creation of the iron center, there is wastage in the current stream. 

•It gives out parcel of warmth which requires cooling. This makes a break in the progression of the current.

Current|voltage|difference between current and voltage

   

What is the difference between voltage and current?

What is current?

 We know that when electrons start flowing from one place to another in a conductor, current is generated in it due to the flow of electrons.

 Therefore, the rate of flow of electrons in unit time from a point is called current.

 Hence the rate of charge flow at a point is called current. The current is measured in ampere.

 Voltage is the cause of current flow in the same way as water flows from a higher place to a lower place.

 The current is measured with the help of an ammeter, its SI unit is ampere or coulomb / sec.

 Current = Charge / Time

               i = dq / dt

 No current exists without voltage.

 The magnetic field is generated due to current.

 What is voltage?

 A voltage is an electrical force that causes current to flow between any two points, that is, when there is a potential difference between two points, the voltage exerts a force that causes the charge to move from one point to another, causing the circuit to The current starts flowing.

 Therefore, we can say that when there is a difference of charge between two points, it is called voltage. It is measured as a volt, denoted by V. 

 The voltage produces a constant valid force.

I hope this helps you. Thank you ❤️.