Not able to set checkbox default checked while using angularjs

I want to set default value of checkbox to checked ie., user must see that check box is checked when opening the page for some reason it does not work while using angularjs

here is my code

<html ng-app>

    <input type="radio" name="lookup"  ng-model="lookup" value="1" ng-checked="lookup==1" checked>Employee Lookup</input>
    <input type="radio" name="lookup"  ng-model="lookup" value="2" ng-checked="lookup==2">Company Lookup</input>
</html>

Since you're using ngModel and value, the radio will automatically be selected if they match. Here is the HTML and JS:

<html ng-app ng-controller="testcontroller">
  <input type="radio" ng-model="lookup" value="1">Employee Lookup</input>
  <input type="radio" ng-model="lookup" value="2">Company Lookup</input>
</html>

function testcontroller($scope){
  $scope.lookup = 1;
}

And here is a working jsFiddle demonstration: http://jsfiddle.net/BinaryMuse/ZQDts/3/ (You might have been having trouble with your jsFiddle because you misspelled ng-app.)