How to type mathematical equations in MS WORD

If you want to insert an equation in your documents using MS WORD follow these  steps.
Step1: Open MS WORD.
Step2: click n INSERT.
Step3: click on MATHEMATICAL EQUATION.
Step4: you can see different patterns on the top click on the pattern type which you want to insert.

Distribution factor

It is defined as the ratio of EMF PRODUCED PER PHASE in Distributed winding to that of Concentrated winding. It is  denoted by Kd.
Let us derive the equation for kd.
Let us consider a 2 Pole synchronous machine with 12 slots in stator and with full pitch winding(i.e coil span is equal to 180°electrical. The total electrical angle is equal to 360° (180*2).
Electrical angle is calculated by formula
   Electrical angle=(number of poles*180°)
Number of slots per pole is equal to 6 ((12/(2)).
[Formula:
Number of slots per pole is given by the ratio of number of slots to that of number of poles.]
Number of slots per pole per phase is equal to 2 (6/3).
[Formula:
Number of slots per pole per phase is given by the ratio of number of slots per pole to that of number of phases.]
Slot angle is equal to 30° ((180*2)/12)
[Formula:
Slot angle=
((No of poles*180)/(total no of slots))]
Let us draw armature winding(only for one phase).
It is shown clearly in the photographs.
The emfs  E1 and E2 in the coil side 1 and 2 will be in same phase.
And the emfs E3 and E4 are in the same phase and their resultant will be lagging by an angle with the resultant of E1 and E2.
Their vectors are shown in the figure 2.
Let us assume that their are n turns and'Q' (some times represented as alpha during explanation)be  the slot angle then the vector diagram is shown in the figure. Let us draw perpendicular bisectors of all the vectors.Perpendicular bisectors meet at a point O as shown in the figure 3.
Let Er be the total emf induced in the distributed winding per phase and From Fig3
Er=ci=2yc=2*oc*sin(nQ/2)[from fig 3]
In case of concentrated winding the they use only two slots and hence emf induced in the coil sides are equal(coil span=180°).
Let ct is the emf induced in each coil side
Hence each phase has 2 coil sides and n turns, So total emf induce is given by
E=2*n*ct=2*n*oc*sin(Q/2).[from fig3]
Distribution factor(Kd)=((emf induced per phase in case of distributed winding)/(emf induced in case of concentrated winding))
Kd=[(2*oc*sin(nQ/2))]/[2*oc*n*sin(Q/2)]
=[sin(nQ/2)]/[n*sin(Q/2)]
By using above formula we can calculate distribution factor where
n = the number of slots per pole per phase.
Q=slot angle.

How to calculate the multiplication factor of a wattmeter

Multiplication factor=(Voltage range*current range*power factor)/(full scale deflection)

Cost of printing different Indian currency

In our daily life we are using different Indian currency. Have you ever thought about the amount our government   is spending in printing different kinds of notes(Rs50 note,Rs100 note,etc.)

It costs 50paise for printing 5RS note.
It costs 96paise for printing 10RS note.
It costs 1.5Rupees for printing 20Rupees note.
It costs 1.81Rupees for printing 50Rupees note.
It costs 1.70Rupees for printing 100Rupees note.
It costs 3.58Rupees for printing 500Rupees note.
It costs 4.06Rupees for printing 1000Rupees note.

Can we produce electricity using silk moth cocoons?

Scientists are  saying that electricity can be produced by using  silk moth cocoons.
The membrane of silk moth cocoon contains many elements such as copper,magnesium, sulphur ,etc.
Mobile charge carriers are formed by the elements in the cocoon if  we wet the cocoon. So scientists inserted a copper rod on the outer surface of the wet cocoon and aluminum rod in the inner surface of the same cocoon. They connected a small led bulb between them. The bulb has blown for 1min.

C program for PALINDROME NUMBERS

Program to check weather the number is palindrome number or  not?
#include<stdio.h>
int main()
{
int num,a,b,rev,sum=0;
scanf("%d",&num);
b=num;
while(num>0)
{
a=num%10;
sum=sum*10+a;
num=num/10;
}
if(sum==b)
printf("yes");
else
printf("no");
return 0;
}

What is meant by linear wave shaping?

If we give a input signal(it may be in form of sinusoidal or square or ramp or etc..)  to a low pass circuit we will get some distortion in output signal this is called as linear wave shaping.

Low pass circuit: A low pass circuit is that  which gives output signal only at low frequencies i.e even if we give input at high and mid band frequencies we will not get output

Interesting thing about the squirrel cage type and wound type rotor

In both type of rotors the rotor slots will not be in  parallel with rotor shaft axis, this is done to get smoother operation.

DC generators

When are separately excited DC generators used?
Ans: If we want wide range of output voltage then SEPARATELY EXCITED DC GENERATORS are used.

But if want to maintain constant terminal voltage then we have to use CUMULATIVELY COMPOUNDED SELF EXCITED GENERATORS.

Function to return the quotient

int divide(int a,int b)
{
int c=a/b;
if((c>=1)&&(a%b==0))
return c;
else
return -1;
}

Why DC series motors are not started with out load

If we start DC series motor with out load the speed increases which in turn  increases back EMF(proportional to speed) but due to increase in back EMF armature current decreases. Since field winding is in series the flux also decreases due to decrease in the armature current. We know that flux is inversely proportional to speed, so decrease in flux causes increase in speed. This process continues.

Theoretically speed reaches to infinity as flux tends to zero.

Practically due to high speeds the bearings,armature shaft,etc get damaged.

So keep in mind never start a DC series motor at no load.

C program for sum of powers of numbers

#include<stdio.h>
int main()
{
int a,s;
scanf("%d",&a);
s=((6*a*a*a*a*a)+(15*a*a*a*a)+(10*a*a*a)-a)/30;
printf("%d",s);
return 0;
}

C program for sum of adjacent pairs

#include<stdio.h>
int main()
{
int a,b,s;
scanf("%d %d",&a,&b);
s=0;
while(!(b==-1))
{
s=a+b;
a=b;
scanf("%d",&b);
printf("%d",s);
if(b!=-1)
printf(" ");
if(b==-1)
printf("\n");
}
return 0;
}

C program for inverted right triangle

#include<stdio.h>
int main()
{
int n,i,j,t,m;
scanf("%d",&n);
m=n;
for(i=0;i<m;i++)
  {
  t=i;
for(j=0;j<n;j++)
  {
  i=i+1;
   if(i<=9)
     printf("%d",i);
   if(i>=10)
     printf("%d",i%10);
  }
  n=n-1;
   printf(" \n ");
  i=t;
  }
return 0;
}

C program to find second largest element

#include<stdio.h>
int main()
{
int a,b,temp,t;
scanf("%d%d",&a,&b);
if(a<b)
{
 t=a;
 a=b;
 b=t;
}
scanf("%d",&temp);
while(temp!=-1)
{
 if(temp<b)
 scanf("%d",&temp);
 else if(temp>b)
 {
 b=temp;
 scanf("%d",&temp);
 }
 if(a<b)
 {
 t=a;
 a=b;
 b=t;
 }
}
printf("%d",b);
return 0;
}

Pythagorean triples

#include<stdio.h>
int main()
{
int a,b,c;
scanf("%d %d %d",&a,&b,&c);
if((a*a)==(b*b)+(c*c))
printf("yes");
else if((b*b)==(c*c)+(a*a))
printf("yes");
else if((c*c)==(a*a)+(b*b))
printf("yes");
else
 printf("no");
return 0;
}

How three phase system reduces the copper loss

Consider a 5KW load.If a single phase system it then we require 2 wires,one carrying the current towards the load and other carrying current away from the load. Assume that the applied voltage is 100V  then the current is 30A.if we see the copper losses in it(if resistance of each wire is 1 ohm) the Total copper loss is 1800 watts (900+900).
Now consider a three phase balanced supply.It has three wires each carrying 10 amps current then calculate the losses which are less when compared to that of single phase.

STRUCTURE OF AN ATOM

We know that the size of atom is so small that it can not be seen with the most powerful microscope 🔬.

Then a doubt arises in our mind,how did scientists determined its structure?

They adopted a alternative method in which they will first studied the properties of an atom and on that basis they have determined its possible structure.

So always keep in mind that structure of an atom is determined on the basis of its properties but not by seeing it.

Retardation test of DC SHUNT MACHINE:

Retardation test (or) running 🏃 down test of dc machine
This method is used to find the constant losses(friction + windage + iron losses)

This is also a noload test. We can calculate the efficiency of a dc machine by knowing the armature amd shunt copper losses at a given load.

Consider a DC SHUNT MOTOR running at noload.
If the supply to the
                                   1.Armature is cut off 📴 and the supply to the field remains same then the KINETIC ENERGY ⚡ is used to overcome (friction + Windage +Field copper ) no load losses
                                   2.Armature as well as field to the field is cut off then the KINETIC ENERGY ⚡ is Used to overcome only the friction losses  + Windage losses.  (their will be no field copper loss because in second case their is no supply to the field)

How to conduct it:
It is very easy to conduct it we have to remove the supply and calculate the rate at which the speed falls.

Losses can be calculated by using formula (derivation):

     Since kinetic energy ⚡ is used to overcome losses:

                  W=(d(Iw^2)/2dt)
where     w(omega)= 2πN/60  in rad/sec
         
On differentiation we get
                   W= 2Iw (dw/dt)
Now substitute w= 2πN/60.
We get
                W= (((2π)÷(60))^2)(IN(dN/dt))

Where
          I=Moment of inertia of armature.
          N=speed of armature in rpm.

Accordingly  if the supply to the armature is cut off and supply to field is not cut off then 'W' indicates friction +windage+Field copper losses.

If supply to both armature as well as the field is Cut Off Then 'W' indicates only Friction + Windage Losses.

To find I:
                But it is difficult to find the moment of inertia of Armature i.e 'I' . It can be easily found by conducting another experiment

Firstly,the retardation test is conducted and dN/dt1 is noted

Secondly,the shaft of the motor is keyed to the flywheel 🎡 of known moment of inertia I1 and the time for the fall of same speed is noted i.e dN/dt2

Since in both cases same motor is used so losses are equal

Losses in case1:
W= (((2π)÷(60))^2)(IN(dN/dt1))

Losses in case2:
W=(((2π)÷(60))^2)((I+I1)N(dN/dt2))

N=speed in rpm
I=Moment of inertia of armature.
I1=Moment of inertia of flywheel
Equating above two equations we get I value if I1 value is known

Hence by retardation test we can calculate losses.

Worlds largest electricity generating station

The worlds largest electricity generating station is located in china.It is a hydro electric power plant which is across the dam THREE GORGES DAM. Its generating capacity in watts is 22500.
For generating that much amount of power it employs 32 Francis turbines each of a capacity of 700 MWand two 50 MW turbines.
32*700=22400 MW
02*50 =     100 MW
Total. =22500 MW

Father of battery

An 18th century scientist named ALESSANDRO VOLTA developed a voltaic pile which was later developed into battery 🔋.VOLTAGE is named after him.

BOEING COMPANY(EVERY ELECTRICAL ENGINEER MUST KNOW ABOUT IT)

It is one of multinational companies.It manufacturers airplanes and many other military equipments like missiles etc.,
It was sarted by WILLIAM E BOEING.He studied at YALE UNIVERSITY. He worked initally in a timber industry and he became wealthy and known about wooden structures.Slowly he built a seaplane and built ships. And it satarted to manufacture different types of planes which are used for wars.

Weight affect growth rate

Hai friends,
Please give one minute of your precious time and read this article.
Do you know one of cause for decrease in growth rate(the rate at which our height increases) in present generations is carrying weights.Many of the servays says that weight lifting affects the growth rate.Weight lifting decreases the growth rate or stops the growth. We may think that we are not carrying any weights it is obsoletely wrong but we have carried and even now every child is carrying a lot of weight daily .I mean from our nursery to 🔟 th class we have many books 📚 to carry.Every day we used to carry a lot of books 📚 from home 🏡 to school and from school to home.(CHILDHOOD IS THE MAJOR PART WHERE WE GROW MORE HEIGHT )

As I have already said that carrying weights decreases the growth rate.
So i want to make you aware about this and say to children 🚸 not carry books 📚 daily from home 🏡 to school 🏫 and from school 🏫 to home 🏡 instead they may keep their books in school.

I am not saying that if we doesn't carry books 📚 we will become height,but I am  saying about a factor which affects our height.
You can take a live example:
Our parents and grandparents have also studied to some extent.Many of us are lesser in height compared to them it is because in their childhood they have very less books 📚.

Share this if you agree.
         .   😊  M.CHAITANYA KUMAR REDDY

Dual networks

Two ✌ circuits are said to be duals of each other if cut set matrix of one circuit equal to the tieset matrix the later

Advantages of employing THREE phase circuits

1. For a given size of machine 3 phase machines provides more Output compared to that of single phase machines.
2.The amount of copper required to transfer power is less in three phase circuit when compared to that of single circuit
3.Transmission of power using three phase has more efficiency compared to that of single phase
4.Three phase has good voltage regulation compared to single phase
5.For a given size of rating three phase machines are smaller in size compared to that of single phase
6.Three phase circuits can produce rotating magnetic field where as single phase cannot
7.Three phase motors are self starting,where as single phase motors are not self starting
8.Three phase motors have less pulses where as single phase motors have more pulses,So the torque produced by three phase is uniform torque and the torque produced by single phase is uniform torque
9.The equipment of three phase has less losses when compared to that of single phase
10.If Six or twelve phase supply is provided to the rectifier then the output has less ripples

How to swap three numbers in MATLAB with out using a temporary variable

%DECLARING THE VALUES OF A%

a=1;
b=2;
c=3;

% Code for swapping %

a=a+b+c;
b=a-b-c;
c=a-b-c;
a=a-b-c;

%PRINTING THE SWAPPED VARIABLES%

a
b
c

FLEMINGS LEFT HAND RULE

Flemings right hand rule is used to identify the direction of induced current when a conductor cuts the magnetic field

Stretch the THUMB,FIRST FINGER,MIDDLE FINGER OF YOUR RIGHT HAND MUTUALLY PERPENDICULAR
IF THUMB SHOWS THE DIRECTION OF FORCE AND
FIRST FINGER REPRESENTS THE DIRECTION OF MAGNETIC FIELD
THEN MIDDLE FINGER REPRESENTS THE DIRECTION OF CURRENT

Note that Flemings right hand rule is used only for generator
But not for motor

Easy ways to remember:

1.  [Flemings right hand rule]=[generator]
Both the words have two R's it is one way of remembering that Flemings right hand is used for generator

2.  FBI
F(force)-THUMB
B(magnetic field)-FIRST FINGER
I(current)- middle finger

CAN ELECTRICITY PASS THROUGH PENCIL LED

Yes,because pencil led is made of GRAPHITE which is a conductor of electricity

Who used the word electricity for first time

The word electric was first used by Francis
Bacon to describe materials like amber that
attracted other objects.