int m;  // initialise variable m
float n; //initialise variable n

void setup()
{  
pinMode(A0,INPUT);  // set pin a0 as input pin  Serial.begin(9600);// begin serial 
                                       communication between Arduino and pc
}

void loop()
{  
m=analogRead(A0);   // read analog values from pin A0 across capacitor   
n=(m* .304177);    // converts analog value(x) into input ac supply value using this 
                            formula 
Serial.print("   analaog input  " ) ;   // specify name to the corresponding value to 
                                                         be printed   
Serial.print(m) ; // print input analog value on serial monitor  
Serial.print("   ac voltage  ") ; // specify name to the corresponding value to be 
                                                  printed   
Serial.print(n) ; // prints the ac value on Serial monitor   
Serial.println();
}