enqueue script on custom post type archive page

How do I enqueue a script on the header if the user is on an archive page of a custom post type? The custom post type is called limitedrun and the page is called archive-limitedrun.php.

I tried this and got no response:

function opby_theme() {
wp_register_script('responsive-img', get_template_directory_uri() .'/js/responsive-img.min.js', array('jquery'));
wp_enqueue_script('responsive-img');
wp_enqueue_style( 'opby', get_stylesheet_uri() );
wp_register_style('googleFonts', 'https://fonts.googleapis.co/css?family=Roboto+Slab:400,100|Bitter');
wp_enqueue_style( 'googleFonts');
if (is_singular('limitedrun') ) {
wp_register_style('ltd-run-font', 'https://fonts.googleapis.com/css?family=Roboto:100,500');
wp_enqueue_style( 'ltd-run-font');
}
}
add_action( 'wp_enqueue_scripts', 'opby_theme' );  

You can save your time and server load by not using wp_register_script and wp_register_style when you don’t need them definitely. wp_enqueue_style and wp_enqueue_script do the same job themselves when not involving excessive functions.

Here is easier and more readable code up to date with the accepted answer by @vancoder:

<?php
function opby_theme()
{
    wp_enqueue_script(
        'responsive-img',
         get_template_directory_uri() .'/js/responsive-img.min.js',
         array('jquery')
    );

    wp_enqueue_style(
        'opby',
        get_stylesheet_uri()
    );

    wp_enqueue_style(
        'googleFonts',
        'https://fonts.googleapis.co/css?family=Roboto+Slab:400,100|Bitter'
    );

    if ( is_post_type_archive('limitedrun') ) {
        wp_enqueue_style(
            'ltd-run-font',
            'https://fonts.googleapis.com/css?family=Roboto:100,500'
        );
    }
}
add_action( 'wp_enqueue_scripts', 'opby_theme' );