angular js ng-repeat a radio button list from scope with a default checked

<!DOCTYPE html>
<html>
<head>
    <script src="https://code.angularjs.org/1.3.0-beta.5/angular.js"></script>
    <script>
        var app = angular.module("radioApp", []);
        app.controller('radioCtrl', function ($scope, $rootScope) {
            $scope.radii = [{
                price: '$10',
                checked: true,
                name: "Messaging Value Packes"
            }, {
                price: '$10',
                checked: false,
                name: "International Value Packs"
            }];


            $scope.handleRadioClick = function (radius) {
                alert(radius.price);
            };
        });
    </script>
</head>
<body ng-app="radioApp" ng-controller="radioCtrl">
  <h1>Radio button list default checked</h1>
    <div ng-repeat="radius in radii" id="radio-{{radius.price}}">
        <label>
            <input type="radio" name="radius" ng-checked="radius.checked" ng-change="handleRadioClick(radius)" ng-model="selectedValue.price" value="{{radius.price}}">{{radius.name}}
        </label>
    </div>
     
  <div><br/><br/><a href="http://www.code-sample.com" target="_blank">Go more...</a></div>
</body>
</html>

// Code goes here

/* Styles go here */