如何在wordpress中查找帖子类别源文件

I create a post category and sub category then add to menu now i want to echo some specific data for each specific category page but i can not find the source file in theme directory.

I also use firebug inspect element but it show only html help me to find exact php source file thanks.

Here is my code.

<?php

        $current_user = wp_get_current_user();

        if ( is_category( 'nokia' ) ) {
          echo "<h1> i am iqbal</h1>"
    ?>
    <h1>  i am iqbal </h1> 

<!-- HTML markup here -->

<?php } else { ?>
<h1>
     i am not iqbal
</h1>
<!-- other HTML markup here -->

<?php } ?>