Managing different Service Application for different web application

To explain the scenario, we have a SharePoint farm with cababilities for Enterprise search (Web1) and Fast Search (Web2). The following steps details on how to do it:

1.  Go to Central administration --> Application management and on the Application management page click on "Manage Web Applications"
2. From the ribbon select "New" button, in the "Create New Web Application" page fill in the required information and select "Custom" in section "Service Application Connections" as shown below:

Select the required services applicable for this web application and complete the web application creation.