Can we use our own specific charactor in the place of $ sigh in Jquery?

ANS :- Yes
You can also create your own shortcut very easily. The noConflict() method returns a reference to jQuery, that you can save in a variable, for later use. Here is an example
    var kk= $.noConflict();

     kk(document).ready(function () {
         kk("button").click(function () {
             kk("p").text("jQuery is still working!");
         });
     });