How to show selected value in select options angular js

<select name="our_cal_type" ng-init="our_cal_type='P'" ng-model="our_cal_type">
                    <option value="R">Rs</option>
                    <option value="P">%</option>
                  </select>

ng-init : if our_cal_type is then in the option elements an option tag where value is P. Its automatically selected..

or 

<div ng-app="testApp">
    <div ng-controller="MainCtrl">
        <select>
            <option ng-repeat="rate in rates track by $index" ng-selected="{{rate.name=='pound'}}">
               {{rate.name}}
            </option>
        </select>
    </div>
</div>



var app = angular.module("testApp", []);

app.controller("MainCtrl", function($scope){
   
    $scope.rates = [
        { 'name': 'dolar', 'is_default': true},
        { 'name': 'pound', 'is_default': false},
        { 'name': 'euro', 'is_default': true}
    ];
   
});