angularjs $rootScope.watch not working

I am new to angularjs. I am trying to learn $watch property . Here is my plunker.

rootScope.$watch property is executing on page load only and not on text change event. But it works properly with $scope.$watch.

Solution

It will work if you turn it to Object , like:

  $rootScope.name = { value:'World'};

And bind it like:

  <input type="text" ng-model="name.value"></input>