Couldn't find grecaptcha with $.getScript in v2.0

In v1.0, it's possible to retrieve the source js code from http://bit.ly/1HUdC5V with $.getScript, and all the functions inside are avaible to be called. But in v2.0, there seems to be no way to do something similar. For example, I've tried $.getScript('http://bit.ly/1yJFa7U'), but I couldn't load functions like grecaptcha.getResponse(). If I tried to render the widget explicitly with $.getScript('http://bit.ly/1F9td1D'), neither this line would fire the function onloadCallback().Was there anything wrong when I do this? Or I have to load the source code using