Shrutika,

The Default View only changes the default for users with Edit permissions for the module. Visitors (without Edit permission) will only ever see Current announcements.

This can be a bit tricky to understand why it works that way (because many people expect the behavior that you are looking for). In old versions of the Announcements module, Editors had no way of accessing Expired or Future announcements.

You could use the Reports module to create an output pulling from the Announcements table to get what you want.

Otherwise, you're really looking at using a different module (look for News type modules....if Ventrian wasn't ending their modules, I'd recommend the Ventrian News Articles module).