I found the solution:
To change particular or any http call to https call, put the code in
VirtualHost :80
ErrorLog /var/log/httpd/error_log
CustomLog logs/access.log common
LogLevel info
RewriteCond %{HTTPS} off
RewriteEngine On
RewriteRule ^(.*)$ https://%{HTTP_HOST}$1 [R=301,L]
RewriteEngine On