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;
}