I'd use SimpleXMLElement.

<?php

$xml = new SimpleXMLElement('<xml/>');

for (i <= 8; ++$i) {
    $track = $xml->addChild('track');
    $track->addChild('path', "song$i.mp3");
    $track->addChild('title', "Track $i - Track Title");
}

Header('Content-type: text/xml');
print($xml->asXML());

?>

$xml->asXML() can also take a filename as a parameter to save to that file

DOMDocument is a great choice. It's a module specifically designed for creating and manipulating XML documents. You can create a document from scratch, or open existing documents (or strings) and navigate and modify their structures.

$xml = new DOMDocument();
$xml_album = $xml->createElement("Album");
$xml_track = $xml->createElement("Track");
$xml_album->appendChild( $xml_track );
$xml->appendChild( $xml_album );

$xml->save("/tmp/test.xml");

To re-open and write:

$xml = new DOMDocument();
$xml->load('/tmp/test.xml');
$nodes = $xml->getElementsByTagName('Album') ;
if ($nodes->length > 0) {
   //insert some stuff using appendChild()
}

//re-save
$xml->save("/tmp/test.xml");

All you need to do is to add a root element StudentDetails, and append all other elements ti it, like the following:

<?php
$name = $e['name_1'];
$email = $e['email_id'];
$phone_no =$e['phone_no'];

$doc = new DOMDocument();
$doc->formatOutput = true;

$root = $doc->createElement('StudentDetails');
$root = $doc->appendChild($root);

$ele1 = $doc->createElement('StudentName');
$ele1->nodeValue=$name;
$root->appendChild($ele1);

$ele2 = $doc->createElement('FatherEmailId');
$ele2->nodeValue=$email;
$root->appendChild($ele2);

$ele3 = $doc->createElement('PhoneNumber');
$ele3->nodeValue=$phone_no;
$root->appendChild($ele3);

$doc->save('MyXmlFile007.xml');

And the result would be like:

<?xml version="1.0"?>
<StudentDetails>
  <StudentName>Pravin Parayan</StudentName>
  <FatherEmailId>[email protected]</FatherEmailId>
  <PhoneNumber>9000012345</PhoneNumber>
</StudentDetails>

This is probably what you are looking for.

    //Creates XML string and XML document using the DOM 
    $dom = new DomDocument('1.0', 'UTF-8'); 

    //add root
    $root = $dom->appendChild($dom->createElement('Root'));

    //add NodeA element to Root
    $nodeA = $dom->createElement('NodeA');
    $root->appendChild($nodeA);

    // Appending attr1 and attr2 to the NodeA element
    $attr = $dom->createAttribute('attr1');
    $attr->appendChild($dom->createTextNode('some text'));
    $nodeA->appendChild($attr);
/*
** insert more nodes
*/

    $dom->formatOutput = true; // set the formatOutput attribute of domDocument to true

    // save XML as string or file 
    $test1 = $dom->saveXML(); // put string in test1
    $dom->save('test1.xml'); // save as file

For more information, have a look at the DOM Documentation.

To do what you want:

    //Creates XML string and XML document using the DOM 
    $dom = new DomDocument('1.0', 'UTF-8'); 

    //add root == jukebox
    $jukebox = $dom->appendChild($dom->createElement('jukebox'));

    for ($i = 0; $i < count($arrayWithTracks); $i++) {

        //add track element to jukebox
        $track = $dom->createElement('track');
        $jukebox->appendChild($track);

        // Appending attributes to track
        $attr = $dom->createAttribute('source');
        $attr->appendChild($dom->createTextNode($arrayWithTracks[$i]['source']));
        $track->appendChild($attr);
        $attr = $dom->createAttribute('artist');
        $attr->appendChild($dom->createTextNode($arrayWithTracks[$i]['artist']));
        $track->appendChild($attr);
        $attr = $dom->createAttribute('album');
        $attr->appendChild($dom->createTextNode($arrayWithTracks[$i]['album']));
        $track->appendChild($attr);
        $attr = $dom->createAttribute('title');
        $attr->appendChild($dom->createTextNode($arrayWithTracks[$i]['title']));
        $track->appendChild($attr);
    }

    $dom->formatOutput = true; // set the formatOutput attribute of domDocument to true

    // save XML as string or file 
    $test1 = $dom->saveXML(); // put string in test1
    $dom->save('test1.xml'); // save as file

Cheers