Sign in as different user in SharePoint 2013

I have created a team site http://sp2013srv/ in which i wanted to test some functionality with different user. But “Sign in as different user” link was missing.

signinasdifferentuser.png

So how to sign in as different user in SharePoint 2013? You can directly use the following URL to sign in as different user http://sp2013srv/_layouts/closeConnection.aspx?loginasanotheruser=true