jQuery to Reset sharepoint Dropdown value to empty in

Can you please let me know how to reset Dropdown value to empty using jQuery.

I tried using like this on Dropdown doen changed event but it is not working. Can you please help me. Below is the code i tried

$("select[title='"+Hide_Column+"']option:first-child").attr("selected", "selected");


$(document).ready(function(){
CheckDropdown("Drop1","Drop2");
CheckDropdown("Drop2","Drop3");
}); 
DropDownColum.change(function() {
var DropDownColum=$("select[title='"+Drop_Column+"']");
var value = $(this).val();// Value of selected option
        var Text = $(this).val();// Text of selected option
       // alert('Value: '+value);
       // alert('Text:' +Text);
if (Text == "")
{
$("select[title='"+Hide_Column+"']option:first-child").attr("selected", "selected");    
HideColumn(Hide_Column,"True");
} 
else
{
HideColumn(Hide_Column,"False");
}
});
function HideColumn(Column,IsHide)
{    
     if(IsHide=="True")
     {  
        $('nobr:contains("'+Column+'")').closest('tr').hide();
     }
     else
     { 
        $('nobr:contains("'+Column+'")').closest('tr').show();


 }
 }