In this we can see how to make the google reCAPTCHA v2 as responsive for mobile devices.Thats very simple
Just add the below style code in your css
@media screen and (max-width: 575px) {
#rc-imageselect, .g-recaptcha
{
transform:scale(0.77);
-webkit-transform:scale(0.77);transform-origin:0 0;
-webkit-transform-origin:0 0;
}
}
